Nomenclature of Organic Compounds 9781842654828

Citation preview

Nomenclature of

Organictee

Revised Edition

| mmer suk

|

Se

as :

Alphas :

- Science:

Nomenclature of Organic Compounds Revised Edition

Nomenclature of Organic Compounds Revised

Edition

Suey ral

© Alpha Science International Ltd. Oxford

Nomenclature of Organic Compounds

172 pgs | 17 tbs. |21 figs.

S.C. Pal Department of Chemistry Midnapore College Midnapore, West Bengal Copyright © 2006, 2008 Revised edition 2008

ALPHA SCIENCE INTERNATIONAL LTD.

7200 The Quorum, Oxford Business Park North

Garsington Road, Oxford OX4 2JZ, U.K.

www.alphasci.com All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior written permission of the publisher. Printed from the camera-ready copy provided by the Author.

ISBN 978-1-84265-482-8 Printed in India

To My Parents

Preface I have seen many bright students of chemistry who are a little weak in naming an organic compound. Some find little interest in the topic. Given a name, one cannot write its reactions or synthesis unless one diagnoses its structure properly. True, there are software programs available these days to generate name from a structure. But these cannot be tools for learning the topic. Again just naming an organic compound for a particular structure does not serve the whole purpose. One must learn to identify the characteristic groups or functionalities to predict its properties or design a synthesis. I have tried to write this book with all these requirements in mind. I have attempted to create interest for the up-coming students of chemistry by dealing the subject in various ways. A relatively large exercise (with some solved problems) in such a small book is also made to this effect. I have just tried to present the topic as a game. It is up to the readers to judge.

Some errors are likely to creep in. I solicit criticism and suggestions from the readers with gratitude.

S.C. Pal

Acknowledgements | acknowledge the help of my colleagues who also encouraged me throughout the work. Dr. D. Mal of IIT, Kharagpur; Dr. Kumaresh Ghosh, Kalyani University and Dr. Pulak Ganguly, Narendrapur Ramkrishna Residential College; Sajal Mal, Research fellow, IIT, Kharagpur helped me by discussion and providing books or in other ways. I am grateful to all of them. Many of my past students who are now well established (to name some of them: Dr. Dipankar Das, Research Associate, University of Alberto, Canada; Dr. Nirmal Hazra, City College, Kolkata; Prasanta Ghorai and Anirban Bhunia, both Research fellows, Germany; Gourisankar Maity, Teacher; Apurba Das, Research fellow, IACS, Jadavpur; Pranab Haldar, Research fellow, IIT, Kharagpur) encouraged me to carry on writing books. Some of my present students (Arpita Bose, Ayan Dasgupta, Santanu Pyne, Sutanuka Pal,

Tridib Bhunia) assisted me in preparing the index. I acknowledge their encouragement and assistance. I take this opportunity to thank Dr. P. K. Chakraborty, Principal and Arindam Dasgupta of Computer Department of our college who assisted me with their computer knowledge in course of editing the book. My family members, specially my wife, inspired me and cooperated with me all along. | am indebted to them. Finally I must thank Mr. N. K. Mehra of Narosa Publishing House who decided to present the work in print.

S. C. Pal

Contents Preface Acknowledgements

1. Introduction 1.1 Introduction 1.2 Types of Names 1.3. Historical 2. Guidelines for Naming 2.1 Principles of Naming Lad Guidelines for Naming 2.2.1 A Diagrammatic Sketch to show How the Names of Different Parts are assembled into a Complete Name Parent Identification 23 2.3.1 Parent Selection 2.4 Characteristic (Functional) Groups 2.4.1 Identification of Characteristic Groups 2.) Numbering the Parent Chain

2.5.1 Some More Examples of Numbering 265

2.5.2 Deletion of Locant in Unambiguous Cases Naming of Substituents 2.6.1 Substituents Derived from Parent Hydrides 2.6.2 Substituents having Unsaturation: Alkenyl and Alkynyl Groups 2.6.3 Branched Alkyl / Alkanyl Substituents 2.6.4 Multivalent Radicals 2.6.5 Substituted Substituents

3. Substitutive Nomenclature of Specific Type of Compounds Saturated (Cyclic and Acyclic) and Aromatic Hydrocarbons 3.1 3.1.1 Unbranched Hydrocarbons 3.1.2 Branched Hydrocarbons 3.1.3 Bridged Compounds 3.1.4 Bridged Cyclic Systems with more Rings

pa — Nw

xii Contents

=

3.1.5 Spiro Compounds 3.1.6 Ring Assemblies 3.1.7 Cyclophanes Saturated Compounds having only those Characteristic Groups that are Always cited as Prefix in Substitutive Nomenclature 3.2.1

ie)

3.3.1

3.4

Ethers, Halides, Azo-, Nitro- and Nitrosocompounds, Azides

3.2.2 Acetals and Ketals 3.2.3. Crown Ethers Unsaturated Compounds with or without Functional Groups Which are cited as Prefix Unsaturated Ethers, Halogenocompounds, etc.

Compounds having One Kind of Principal Characteristic Group to be cited as Suffix 3.4.1 Amines & Imines 3.4.2 Alcohols, Phenols and Their Thio-analogues

3.4.3 Carboxylic Acids, Acid Halides, Aldehydes, Nitriles, Amides and Some More Derivatives of Acids 3.4.4 Sulfur Acids and their Derivatives 3.4.5 Anhydrides of Acids (Carboxylic and Sulfonic) 3.4.6 Esters and Salts of Acids 3.4.7 Secondary and Tertiary amides (Carboxamides & Sulfonamides); N-Substituted Hydrazides 3.4.8 Imides

3.4.9 Some Less Commonly Encountered Derivatives of Acids: Amidines, Hydroxamic acids, Carbonic acid derivatives

BD

3.4.10 Ketones and Ketenes 3.4.11 Lactones and Lactams Some Other Specific Types of Compounds / Species 3.5.1 Organometallic Compounds 3.5.2 Isotopically Modified Compounds 3.5.3. Names involving Mononuclear Parent Hydrides 3.5.4 Naming of Anions, Cations and Radicals Compounds having at least Two Different Characteristic Groups that are cited as Suffix Systematic Approaches to name a Compound by Substitutive Nomenclature Functionality Variation with the Same Skeleton To Deduce Structure from the Name

4. Nomenclature other than Substitutive Types 4.1 Replacement Nomenclature 4.2 Functional Class Nomenclature 4.2.1 Radicofunctional Namés 4.2.2 Functional Modifier

Contents 4.3.

Hantzsch-Wideman Nomenclature (for Heterocyclic Compounds)

4.9

4.3.1 Lactones, Lactams, Cyclic anhydrides and Cyclic imides Fusion Names (for Fused Ring Compounds) Conjunctive Nomenclature Additive Nomenclature Subtractive Names Multiplicative Nomenclature 4.8.1 Ring assembly names Symmetrically Branched / Substituted Compounds — Comparison of

4.10

Accepted Names To Choose The Type of Name

4.4 4.5. 4.6 4.7 4.8

Exercise

Appendix

Suggested Further Reading Index

Xl

CHAPTER 1

Introduction

1.1 INTRODUCTION A chemical species (compound, ion, radical, etc.) is no doubt best represented by its structure. But this cannot be a verbal communication and not an easy method of written communication, too. A chemical language is hence devised. A nomenclature is a means of easier communication in written or spoken words. Chemists mainly to conceal their works used earlier random nonsystematic names. Some names

are given which indicate their natural source, etc., not their chemical identity (i.e.,

these names are unrelated to their structures.). Now attitudes of chemists have changed. They want to communicate their achievements (except patents!) to others. A nomenclature is required to define a structure uniquely and to indicate chemical relationship to other compounds also. Systematic names are hence formulated on the basis of some rules and principles. However many traditional names—trivial and semi systematic—are widely used by common

people as also chemists,

e.g., water, acetic acid, ethyl] alcohol, cholesterol,

etc.

Replacing these names by some systematic names, even if simple, may result in the loss of their familiarity. As an example, to name methane as monoane, or water as oxidane will not

receive well acceptance (see Cartoons-I and II, page 140). To name all compounds by one set of rules may lead to undesirable circumstances or may lead to a name that is hardly recognizable. That is only one name following some definite rules, for a particular compound, would not serve the need of general communication. As for example, pentaphenylbenzene (1.1) is easily recognizable but the name ethanepentaylpentabenzene, representing the same compound, is not so. A name e.g., 1-[2Ethoxy-{2-ethoxy-(2-ethoxy(ethoxy))}]propane for compound (1.2) is cumbersome name 3,6,9,12-tetraoxapentadecane for the same compound looks simple.

Ph3C — CHPh» (L.A)

but the

CH3CH, O CH2CH2 O CH2CH2 O CH2CH2 O CH»CH2CH; (le)

2 Nomenclature of Organic Compounds

1.2 TYPES OF NAMES Various types of nomenclature, based on the types of operation, approved / recommended by IUPAC are: 1) Substitutive Nomenclature 2) Functional class Nomenclature 3) Replacement Nomenclature 4) Conjunctive Nomenclature 5) Additive Nomenclature 6) Subtractive Nomenclature

7) Fusion Nomenclature 8) Hantzsch-Widman Nomenclature

9) Multiplicative Nomenclature Actually these are different operations / methods. A single name (unless unsubstituted / unmodified parent hydride) often involves more than one of these operations. Most organic compounds are better named by substitutive system. However other systems give simpler names in many cases. The following examples (Table 1.1) illustrate the importance of different nomenclature methods recommended by IUPAC.

1.3 HISTORICAL Berzelius, Liebig and Wohler tried to systematize organic nomenclature by proposing names of benzoyl chloride and ethyl iodide. On an international basis this started in 1892 in Geneva where 34 leading chemists of European countries met. The main objective was to provide suitable names of aliphatic compounds to facilitate indexing. Later in 1920 International Union of Chemistry (IUC) was organized. In 1930 this organic commissi on published a definitive report of 68 rules. After World War II IUC was changed to IUPAC (1947)International Union of Pure and Applied Chemistry. They attempted to codify and systematize the existing names and accepted a few alternative methods (each systematic in its own way) rather than providing a single name to a compound. Since 1947 the IUPAC has published the following sets of Definitive Rules: Nomenclature of Organic Chemistry, 1947

Nomenclature of Organosilicon Compounds Changes and Additions to Definitive Report Extended list of Radical Name Nomenclature of Organic Chemistry, 1957 Section A: Hydrocarbons Section B: Fundamental Heterocyclic System Nomenclature of Organic Chemistry, 1965

Sections A and B (2™ Edition)

Section C: Characteristic Groups Containing Carbon, Hydrogen, Oxygen, Nitrogen, Halogen, Sulfur, Selenium and / or Telluri um

Introduction 3

Table 1.1: Substitutive names vis-a-vis other IUPAC names Compound

Substitutive Name

CH3CH,CH,I

1-Iodopropane

Other Suitable Name(s) (naming type) Propyl iodide

(1.2a)

(Functional class)

CH;COCH(CH;),

_

3-Methylbutan-2-one

Isopropyl methyl! ketone

(1.2b)

(Functional class)

O peers

Methyloxirane (Hantzsch-Widman)

1,2-Epoxypropane

Propene oxide

(1.2c)

(Additive)

CH;CH,CH,O0CH,CH,OCH, CH,OCH;

1-[2-(2-Methoxyethoxy)

2,5,8-Trioxaundecane

(1.2d)

ethoxy]propane

(Replacement)

2-Carboxymethylcyclohexylethanoic acid

Cyclohexane-1 ,2-diacetic acid

CO,H CO,H

(Conjunctive)

(ive)

7,7-Dimethylbicyclo-

10-Norbornane

[2.2.1]- heptane

(Subtractive)

(1.2f)

laa

~ N CH,CH,CO,H

we)

3-[1H-Indol-1-yl]

1 H-Indolepropanoic acid

propanoic acid

(Conjunctive)

4-[4-Carboxyphenyl] methylbenzoic acid

4,4’-Methylenedibenzoic acid (Multiplicative)

(1.2g)

CO,H (1.2h)

4 Nomenclature of Organic Compounds Table 1.1 contd.

HO,C[CH,], O [CH,], O

Cycloocta-2,4,6-trienyl cation

Homotropylium cation (Additive)

3-[2”’-Carboxyethoxy-

4,7,10-Trioxatrideca-

2’”’-ethoxy-2’-

1,13-dioic acid

ethoxyethoxy]propanoic

(Replacement)

[CH.], O [CH,],CO,H (1.2))

acid

Section C: Characteristic Groups Containing Carbon, Hydrogen, Oxygen, Nitrogen, Halogen, Sulfur, Selenium and / or Tellurium

Nomenclature of Organic Chemistry, 1971

Section A, B, and C (slightly revised; 3 Edition) Nomenclature of Organic Chemistry, 1979

Section A, B, and C (4" Edition)

Section D: Organic Compounds that are not exclusively Carbon, Hydrogen, Oxygen, Nitrogen, Halogen, Sulfur, Selenium and Tellurium. Section E: Stereochemistry (Recommendation, 1974) Section F: Natural Products and Related Compounds (Recommendation,

1976)

Section H: Isotopically Modified Compounds (Recommendation, 1978) Nomenclature of Organic Chemistry, 1993 (Revisions to 1979 Edition).

Since 1993 recommendations are made for the following: Naming Radicals and Ions Class names of Organic Compounds Basic Terminologies of Stereochemistry Naming Fused Rings and Bridged Fused Ring systems Revision to names of Natural Products Principles of Phane Nomenclature

Now the commission is working on for the extension of Phane Nomenclature for naming Fullerenes.

CHAPTER 2

Guidelines for Naming

2.1 PRINCIPLES OF NAMING The structure of an organic compound is regarded, for naming purpose, as consisting of a parent structure that is modified by various structural changes. The name is constructed from a parent name with indication of all those changes. In any nomenclature type the changes, if present, are regarded as being made by replacing the hydrogens’ of parent hydride / any parent structure by other atoms or groups. The latter are called substituents. Substituents are alkyl (or alkanyl) groups or characteristic groups (often called functional groups). These are mentioned either as prefix’ or as suffix’ to the parent name. There are certain rules regarding which groups are to be cited as suffix and which as prefix. Unsaturation (C=C and C=C) can be regarded as subtractive modification® deleting hydrogen atoms at adjacent carbons of the parent structure. This is indicated by changing —‘ane’ ending of the parent name by —‘ene’. In case a functional parent is used naming of the functionalities included in that name is no longer necessary. The complete name is thus an assembled one. It is constructed from one parent name and all substituent names and certain modifications, if present.

Prefix (es) + parent (including any modifications) + suffix

‘In replacement nomenclature heteroatoms are assumed to replace skeletal carbon(s) of parent. Those replacements are named as prefixes (called ‘a’ prefixes, see section-) with appropriate locants. * The name of any substituent that is written before the parent name is called a prefix, and that is written after the parent name is called a suffix. In functional class nomenclature the suffix is a functional class name that is named as a separate word (for details see section-4 .2) *If -ene / -yne is included in parent name then further mentioning is not necessary. In fact any structural part / characteristic group — principal or not is not named further either as suffix or prefix if parent name (trivial) includes it.

6 Nomenclature of Organic Compounds

The position of any change in the parent is indicated by appropriate locant immediately preceding that change. A proper numbering of the parent chain is thus necessary. A repeated occurrence of any structural change is indicated by multiplicative prefix’ after showing all the locants. All the prefixes are cited in alphabetical order in the name.

2.2 GUIDELINES OF NAMING As suggested by IUPAC several alternative names could be constructed for a compound / species depending on the type of nomenclature operations. The nature or rather the structure of the compound is important to decide which operation will be best suited to it. However substitutive nomenclature is better suited to maximum number of compounds. Only when this nomenclature becomes complex, other types of nomenclature are recommended to use (for details see section 4.10). A few nomenclature systems (e.g. additive, subtractive etc.) are recommended only for compounds that are derived from familiar molecules known by common recognized names. Substitutive nomenclature system is discussed first in detail. The following guiding principles may be followed in order: (i) All the characteristic groups (see section 2.4) are identified. The most senior (Tables

2.9 and 2.10) of these is called the principal group. This group, which must have a suffix name, decides: (a) Suffix name to be added to parent (hydrocarbon) name

(b)

Selection of the parent chain viz. root name; it must be linked / part of the parent

chain, in case there is branched skeleton. (c) The numbering of the parent chain: it is given the lowest possible locant.

In absence of any principal characteristic group’ the name will end with —‘ane’ unless there is unsaturation’. (ii) The parent / principal chain is determined. This gives the parent / root name (which also includes any non-detachable prefix e.g. cyclo-, nor-, homo-, etc.). For a choice of the principal chain / ring / ring system in compounds with branched skeleton, see section-2.3.1. (iii) Subtractive modification due to unsaturation’, if present, is made.

“These are basic numeral terms (see Table 2.8).

*These are characteristic groups that have suffix names to be used in substitutive nomenclature (see Table-2.9).

® 7 ane suffix of parent hydrocarbon is replaced by -ene / -yne. In fact, alkene, alkyne (or alkadiene, alkadiyne or alkenyne etc.) etc. were considered earlier as parents to which suffix name of the principal characteristic group is added. However parent is not the same alkene or alkyne always as it is in absence of the principal characteristic group(s). See Appendix - I for illustration and examples.

Guidelines for Naming 7 (iv) All other substituents except the principal group are recognized. These are all named as prefixes (detachable) to parent name.

(v) Appropriate multiplying prefix is added for any of the substituents (including the principal group and unsaturation), if it is present more than once. (vi) The parent chain is numbered properly (see section- 2.5). (vil) The various component names are then assembled. The locant for each substituent

and modification immediately precede the respective name (prefix/suffix). All substitutive prefixes are cited in alphabetical order.

A substituent (principal / primary one) may itself be substituted substituents). The naming of these is discussed in sections-2.6.3 and 2.6.5.

(by secondary

The organization of part names is worked out in a diagram in Section 2.2.1.

2.2.1

A Diagrammatic Sketch to show How the Names of Different Parts are assembled into a Complete Name

Well, do you take the diagram as that of a train! The parent must be the engine, which may have to be modified (due to unsaturation) at times. Substituents are all compartments some of which have cabin(s) [secondary and tertiary substituents]. A front cabin (suffix due to principal characteristic group) is earmarked for the driver (but not required always; automated then?). Compartments are built from the required components separately in a workshop and

then joined to the engine at its back (on the left) one by one (alphabetically, not in order of increasing or decreasing locants!).

Diagram - 1 depicts how structure D-1 is segmented into parts for the purpose of naming, and thereafter part names are assembled. As the structure is made less complex the number of prefixes become lesser, but the number of suffix is always one (may be repeated, D-1) as long as there is a principal characteristic group (D-2, D-3). In absence of any principal characteristic group there will be no suffix name, only -ene/ -yne will replace -ane of parent name (a subtractive modification is called appropriately: it is part of the parent) in case of ‘unsaturation’ (D — 1, 2, 4, 6). Unsaturation may be present in

any substituent — primary (D — 1, 2) or secondary, too. In case functional parent the ‘suffix’ is part of the parent (D — 9). Without any substituent and unsaturation the name of any compound is just the parent name (D — 8; see also section 3.1.1).

In all the above cases the whole name is a single word — no space separates parent from the prefix(es). But in case of an ester the prefix for the alkyl/aryl part of the alcohol is separated by a space from the acid part (parent + prefix to the acid part) (D — 10). The two compartments seem to have no vestibule in between!

8 Nomenclature of Organic Compounds

D-T: 4-4 mino-5-{4-chloro-5-methoxycyclohex-1-en-yf]-2-{ T-methyipropyf]-hex-2-ene -1,6-dioic acid

1 : locant w.r.t. respective primary substi tuent L : locant w.r.t. parent

Diagram - 1

Guidelines for Naming 9

Diagram - 2

Cl

NHCH

‘

D-3:

Diagram-

eee D-4: 2-[2-Chloroethyl]pent-1- en—3 —yne

Diagram — 4

eons ae 5; 5-[1-Beano -1-methoxynonane

Diagram - 5

10 Nomenclature of Organic Compounds

NG Wa

Ee

D-6 Hex-1-ene

se

D-7 1,5-Dichlorohexane

eae yal D-8 Hexane

(on D-9 Phenol

cls

Diagram — 6

O

Begsliter=3 2-Chloroethyl

3-methylbutanoate

D-10

Diagram — 10

2.3 PARENT IDENTIFICATION In substitutive system of naming the parent structure is to be found out. Table 2.1 enlists some of the different types of compounds whose parents are identified. For this all the modifications made are to be foregone, and all the substituents to it are to be replaced by hydrogen. After doing this, the parent structure becom e either (1) A saturated unbranched acyclic or cyclic hydrocarbon (continuous carbon

chain‘) (2) A fully unsaturated cyclic hydrocarbon (conta ining maximum non-cumulated double bonds) (example 2.3g). (3) A functional parent having trivial name that may or may not be a combination of

cyclic and acyclic chains (examples 2.3f, 2.31).

(4) A non-functional parent (with trivial names ) having cyclic plus saturated acyclic

chain(s) (example 2.3n).

*For exceptions see Appendix - II,

Guidelines for Naming 11 Table 2.1: A list of compounds for identification of Parent Structure and Name Name of the compound | Parent Structure Butane

Butane

3-Ethy]-2-methy]

Pentane

3-Chloro-2-methy]butan-2-ol

Butane

(2.3a)

e

(2.3b) Cl

OH (235¢) O 3,3-Dimethyl-5methylaminocyclohexanone

NHCH, (2.3d) fe) CO,H

4-Ethyl-5-oxohexanoic acid

By eh

Cyclohexane

Hexane

(2.3e)

4-Methoxy-

Moo)

NH,

(2.3f) Br

ee

4-Methoxy aniline Cl

¢\

Benzene

benzenamine € \—w,

Aniline

1-Bromo-5-chloro-[10]-

[10}-

annulene

Annulene

(2.3g)

0

CHO

3,4-Dimethoxybutanal

ley

| ea ge Butane

(2.3h) Contd...

next page

12 Nomenclature of Organic Compounds

4-Chloro-3-methyl pyridine

6-Methy]-5-nitro-[ 1]indole

[1H]-Indole

6-Bromo-1-chloro-3-

propy! naphthalene

Naphthalene

-Chloro-5-methylphenol

Phenol

3-Ethanoyl-5-hydroxymethyl] benzoic acid

Benzoic acid

Indane-1,2,3-trione

2-Aza-6,9-dioxa-4thiadecane

N-Methy]-1-[2-methoxyethoxymethylsulfanyl]methanamine 2,3-Epoxybutane 2,3-Dimethyloxirane

Hex-3-ene

Decane (Replacment skeleton) Methanamine Butane

Oxirane

Guidelines for Naming 13

2.3.1 Parent Selection. When there is branched skeleton one chain is to be selected as parent. acyclic and a cyclic chain is also considered to have two separate criteria are examined successively in the listed order until a decision chain should include: 1) Maximum number of principal group cited as suffix (examples OH

ee

O

A compound having an chains. The following is reached. The parent

2.4a—2.4e):

O

peeks

OH OH

|

OH

HO

OH

Ho

hed ie ell OH

Cl

(2.4a)

(2.4b)

Cl

OH

(2.4c)

(2.4d)

(2.4e)

(a) 2-[4-Hydroxybut-2-enyl] propan-1,3-dioic acid (b) 2-[4-Chlorobutyl] butan-1,3-diol (c) 3-[4-Chloro-1-hydroxybut-2-eny!] pentan-2,4-dione

(d) 3-[3-Hydroxypropyl] pentan-1,2,4,5-tetrol (e) 2-Cyclopentylethanal 2)

Maximum number of C=C and C=C bonds together (examples 2.5a — 2.5e):

~

HO,C

Zi

~CO,H

SS

eis

SA =

et

ll

CO,H

(2.5a)

|

(2.5b)

(2.5c)

OO

aw OMe

(2.5d)

(2.5e)

(a) 4-[3-Carboxypropy]] oct-2-en-6-yne-1,8-dioic acid (b) 2-Pentylbut-1-en-3-yne (c) 7-[Prop-1-enyl] undeca-1,3,8-trien-10-yne

(d) 3-Propylhex-1-ene (e) 2-[1-Methoxybutyl] penta-1,4-diene

14 Nomenclature of Organic Compounds 3) Maximum length (examples 2.6a—2.6d):

OH

OH

HO Atg (2.6a)

HO

LA

SN

(2.6b) (2.6c) (a) 3-Hydroxymethylpentan-1,5-diol (b) 5-[1-Hydroxyprop-2-eny]l}nona-3,6-diene-1 ,8-dio] (c) 4,5-Diethenyloct-6-en-1-yne

(2.6d)

(d) 4,5-Diethyloctane

4) Maximum number of C=C bonds (examples 2.7a and 2.7b): go

og

one neat

pm

Nae

HO,C oO

| (2.7a)

\ CO,H

(2.7b) (2.7c) (a) 3-Ethynylpenta-1,4-diene (b) 4-[1-Hydroxyprop-2-yn-1-ylJhepta-2,4-diene-1,7-diol (c) 5-[3-Carboxyprop-1-yn-1-yl]nona-2,7-dien-1,9-dioic acid

5) Lowest locant(s) for principal group(s) (examples 2.8a—2.8c): NH 2 OH OH

HN

map S

oe (2.8a)

©

ees Gis

HN

OMe

O

=

O

(2.8b) (a) 3-[2-Hydroxyethyl]pentan-1,4-diol (b) 5-[3-Aminobut-1-enyl]nona-2,8-diene-1,6-diamine

(c) 7-Methoxy-4-[3-methoxypropanoy]]heptan-2,5-dione 6) Lowest locant(s) for multiple bonds (examples 2.9a and 2.9b):

HO,C

ZA

ZA |

CO,H

OMe (2.8c)

ve

as

msn

CO,H (2.9a) (2.9b) (a) 5-[3-Carboxyprop-2-eny]l]nona-2,6-diene-1,9-dioic acid (b) 4-[Prop-1-enyl]hepta-1,5-diene

Guidelines for Naming 15 7) Lowest locant(s) for double bond(s) (examples 2.10a and 2.10b): S

ZA

Oe

HO


,

-NC, etc.), but many are linked via carbon (e.g. -COOH,

characteristic groups is given in Table 2.2.

-COOR, -CN, etc.) also. A list of

.

Each characteristic group has a definite structure and its linking atom(s) should be shown by free valence(s). This is particularly required for identification of isomeric groups (e.g. -NC and -CN; -NO; and -ONO; -NCO, -CNO, -OCN and -ONC; etc.). In fact bond structure (bond connectivity only) need to be carefully followed for proper identification of a characteristic/functional group. To take an example, (CH3)s;COCH; may wrongly appear as a

ketone, though it is actually an ether (2.14),

Hy

H,C——O-CH, eis

(2.14)

*These are the substituents other than the one cited as suffix in the name.

Guidelines for Naming 17

Table 2.2: A list of Characteristic Groups with their Class names

Number of atoms

Structure of the group

Class name of the Group bromide, iodide)

icethewinrtncOsclint in the’directionofikeEthery 5Hicegie Si -NH-

halen

=NH

Imine

-CN

Nitrile

Isonitil

= (vise -0-ON=

(_N=N*-)

Aldehyde

Se

}

er

;

-SCN

Thiocyanate

are

(Nitro-)"

Nitrite Acid chloride Ester

Others containing more atoms

-COOH -CONH, -SO3H -COOCO-CONHCO-

Carboxylic acid Amide (primary) Sulfonic acid

Anhydride Imide

*These are only prefix names; the compounds containing these characteristic groups cannot be given any functional class name.

18 Nomenclature of Organic Compounds

Many functional groups appear as combination of two or even more functional groups that are directly linked. This is to be carefully noted. Thus O x

—
—

Chloromethy]

Chloromethany]

2-Hydroxypropyl

2-Hydroxypropan-1-yl

1-Methoxy-1-

2-Methoxybutan-2-yl

1-Methy]-2-oxopropyl 2-Carboxy-1-methylethyl

3-Oxobutan-2-yl 1-Carboxypropan-2-yl

3-Carboxy-1-

4-Carboxybutan-2-yl

CH,CH(OH)CH;—

CH;CHAG(OMe)CH, methylpropyl |

CH,C(=O)CHCH, |

HO,CCH,CHCH, |

HO,CCH,CH,CHCH, |

methylpropyl 2-Aminoethy]

2-Aminoethany]

1-Methy]-2-

1-Methanylaminopropan-2-yl

CH,HNCH.CHCH,

methylaminoethy]

| CH,SCH,CHCH,OCH,

2-Methoxy-1-[methy]sulfanylmethyl]ethy]

1-Methoxy-3-methany]lsulfanylpropan-2-yl

1-Carbomethoxy-5methoxycyclopent-2-enyl

1-Carbomethoxy-5-methoxycyclopent-2-en-1-yl

6-Oxocyclohex-3-enyl

6-Oxocyclohex-3-en-1-yl

OMe :

CO,CH, ae

O CICH;

CHOHCH,

|

H,C=CHCHCH,COCH, oa

H

bes; H,CO,H C

Ke

Y

5-Chloromethyl-2-[1- | 5-Chloromethany]-2-[1-hydrhydroxyethyl]cyclohexyl | oxyethanyl]cyclohexan-1-y]

1-(2-Oxopropyl]prop-2-

en-1-yl

1-Carboxymethyl-1ethynylprop-2-en-1-yl

5-Oxohex-1-en-3-yl | 3-Carboxymethanylpent-1-en4-yn-3-yl

|

30 Nomenclature of Organic Compounds

Table 2.8: Basic Numeral Terms* and Parent Names of Saturated Unbranched Hydrocarbons containing as many Carbons Number of Carbons

Numeral Terms

Name of Hydrocarbons

mono tr

_

tetra penta

NOS&S i) oe a\O oO | NO]

30

Lb

Nn=) eSOomyiviieniial

Butane’ Pentane

hexa hepta octa nona deca undeca dodeca Icosa’ Nonaicosa Triaconta

Nonaicosane Triacontane

Tetraconta Pentaconta Hecta Dicta Tricta Kilia

*These are used as multiplying affixes (the terms for repeated occurrence of substituted substituents see Appendix-IV) and for construction of root/parent names of alkanes, alkenes, alkynes, etc. and alkyl groups. Trivial names are the accepted names for first four members. As evident all others are named by adding suffix —ane to the numeral terms with elision of terminal ‘a’ from the numeral term. This terminal ‘a’ is retained if a consonant follows, e.g., buta-1,3-diene. “According to CAS the term is eicosa.

Guidelines for Naming 31

Table 2.9: Principal Characteristic Groups in order of decreasing priority

Class Name

Formula

SEMEL

=

Prefix Name

ee

ee

Suffix Name Excluding C Including C!

ectheprere

Acids: a) carboxylic

-oic acid -sulfonic acid]

b) sulfonic

Anhydride (cyclic & acyclic) — a) acyclic b) cyclic

pipe Tail i Nitrile

|

-carboxylic acid = -------caboxylic anhydride

Acid halide Amide:i) no sub. ii) Sub. at N: a) acyclic b) cyclic

(Meee.

|

Carbamoy]-/ Aminocarbonyl-’ —CONH—

CONT CO

| ~~

N-(R)---amide -lactam

----------

a

-carboxamide |V-(R)--carboxamide -carbolactam

eT is Samide || _-carboximide 1]

—CHO |Formyl-/Oxo | -al_—|_-carbaldehyde_| Ketone opis eon COm sls eeOX0 sur | opener inn -———- |

‘Alcohol& Phenol] —OH [Hydroxy [-ol Thiol

—SH

ulfanyl"/Mercapto

-thiol -mercaptane’

imine 'This name is permitted only when the groups are attached to cyclic system (viz. a ring), or when more than two such alike monovalent groups are directly linked to a parent hydrocarbon. *This prefix name excludes C of the functional group; the C is included in the parent. However this name is recommended in restricted cases (see section 3. 4. 3b) for aldehydes. *This name is preferred to mercapto-. “These are actually prefix endings for monovalent cation / anion substituents, e.g., CH,CH—

: Ethan-1-ylium-1-yl ;

CH,CHCH;—

: Propan-2-id-2-yl

For Functional Class names, and for naming different type of cations and anions see section 3. 5. 4. ®For anions derived from some functional groups by loss of H* from heteroatom see section 3. 5. 4. ’These names are preferred by CAS (Chemical Abstract Service).

32 Nomenclature of Organic Compounds a pe

Table 2.10: Characteristic Groups’ cited only as prefix in Substitutive Nomenclature

Diazo-

Sulfide

/

(R)-sulfanyl -/ (R)-mercapto-

Thioether Halosyl-

*These have no seniority among themselves in selecting parent and deciding direction of numbering the parent chain in substitutive nomenclature. Only when other criteria fail to decide, the substituent cited first (alphabetical) is given priority over the other (see sections 2.3.1 and 2.5 for examples). *These names are used as suffix, written as separate word, in functional class nomenclature and hence these are also called characteristic groups like those given in Table 2.9. Preferred to the other name. * Applicable in case of cyclic ether.

CHAPTER 3

Substitutive Nomenclature

of Specific Type of Compounds

3.1 SATURATED (CYCLIC AND ACYCLIC) AND AROMATIC HYDROCARBONS 3.1.1 Unbranched Hydrocarbons Generic name of saturated hydrocarbons is alkane. Suffix name of these hydrocarbons is ‘-ane’ which is added to the basic numeral term to name the parent hydride. The name obtained thus becomes the name of the unbranched compound (see Table 2.8).

3.1.2 Branched Hydrocarbons Parent selection rules, numbering norms, etc. are given in separate subsections.

3.1.2a Parent Selection for Branched Hydrocarbons To name branched ones, parent is selected first. The choice is made on the basis of the rules (3) & (8) — (10), and in that decreasing order of preference (section 2.3.1) (see examples 8a -

8e later in this section for an exception). These rules with illustrative examples are given below. (3) (8) (9) (10)

Maximum length (ex. 3.1a—3.1d) Maximum number of substituents (ex. 3.2a — 3.2d) Lowest locants for all substituents (ex. 3.3a — 3.3c) Lowest locant for first cited substituent (ex. 3.4).

oe 3-Methylheptane (3. 1a)

an Ethylcyclopropane (3.1b)

Benes 1-Cyclopropyl butane (3.1c)

34 Nomenclature of Organic Compounds

1

eg

;

:

6 pase ain

5-Ethyl-5-propyldecane or,5-Ethyl-5-[propan-1l-yl]-

;

3-Ethyl-2-methylhexane

2,2,5,6-Tetramethyl-4-[1methylpropylJheptane or, 2,2,5,6-Tetramethyl-4-

not, 3-Isopropylhexane

decane

[butan-2-yl]-heptane

(3.1d)

(3.2a)

2

4

(3.2b)

nyl

hexane -2-yl]benzene

not, [4-Methylhexan

not,

1

onane pyl]-2-methyln 4-[{1-Ethylpro ne ntan-3-yl]nona or, 2-Methyl-4-[pehylpropyl]nonane [2-met not,3-Ethyl-4-

(3.2d)

(3.3a)

4-[2-Methylpropy]]1-Methyl-2-[1,3-dimethyl2,2,5-trimethylheptane butyl]cyclopentane or, 4-[2-Methylpropan-2-yl]- or, 1-Methyl-2-[4-methyl2,2,5-trimethylheptane pentan-2- yl]cyclopentane 4-[1-Methylpropyl]2,2,6-trimethylheptane (3.3b)

a

;

4-Methyl-2-phe

(3.26)

2

6

ye pyl1-Methyl-1-pro ne cyclopropa

.

3-Ethy]-5-[1-ethyl-2-methy]butyl]-4-methyldecane or, 3-Ethyl-5-[3-methylhexan-3yl]-4-methyldecane

not,

not,

4-Methyl-2-[2-methylcyclopentyl] pentane (3.5C)

4-Ethyl-5-[2-ethyl-1-methylbutyl]-3-methyldecane (3.4)

3.1.2b Additional Rules of Parent Selection Some additional rules may be required if the above considerations proved indecisive. In

example (3.5) the chain having greatest number of carbons in the smaller side chain (ethyl in

preference to methyl i.e, distribution of carbons

among

substituents

is more

uniform!) is

chosen as parent. In example (3.6) again this criterion becomes indecisive, the parent is now selected with least branched side chain (propyl rather than isopropyl).

Substitutive Nomenclature of Specific Type of Compounds

3-Ethyl-4-[1-methylpropyl]Joctane or, 4-[Butan-2-yl]-3-ethyloctane not, 4-[1-Ethylpropyl]-3-methyloctane. (3.5)

35

5-[1-Isopropylbutyl]-4-propyldecane or, 5-[2-Methylhexan-3-yl]-4-[propan-1-yl]decane not, 4-Isopropyl-5-[1-propylbutyl]decane (3.6)

In examples (3.7a) — (3.7c) the chain with lowest state of hydrogenation (or with highest

state of oxidation) is selected as parent.

a

i

ae

Pentylcyclopentane (3.7a)

Hexylbenzene (3.7b)

Cyclohexylbenzene Gilc)

3.1.2c Compounds with Identical Substituents When identical cyclic substituents are linked to an acyclic chain or identical acyclic substituents are joined to cyclic chain, parent selection rule (8) takes precedence over rule (3) viz., number of substituents is given priority over chain length in deciding parent chain (vide examples 3.8a — 3.8e).

Diphenylmethane (3.8a)

1,2-Diphenylbutane (3.8b)

1,2-Dicyclopentylethane (3.8c)

i Sages ©Os Gx 1,2,3-Tris[2-methylbutyl]cyclopropane or, 1,2,3-Tris[2-methylbutan-2-yl]-

cyclopropane (3.8d)

1,2,4-Triheptylbenzene or,

1,2,4-Tri(heptan-1-yl)benzene

(3.8e)

36 Nomenclature of Organic Compounds

icra ne ee Se

ee

ee

Se

3.1.2d Numbering of the Parent

Numbering pattern i.e., allocation of locants to various substituents to the parent normally

requires application of the numbering rules (i), (iii), (vii) and (viii) (cited in section 2.5) and

in the same order of precedence. The rules with illustrative examples are given bellow. (i)

Fixed numbering (ex. 3.9a and 3.9b)

(iii)

Indicated hydrogen (ex. 3.9.1a)

(vii) Lowest locant for all substituents; decision is made at the first point of difference (ex. 3.10a --3.10e) (viii) Alphabetical preference i.e., first citation (ex. 3.11a—3.11d)

oo

1,8-DimethyInaphthalene (3.9a)

9-Methylanthracene (3.9b)

1-H-Indene (3.9.1a)

eee ipesiota 7-Ethyl-1-methy]-1- naphthalene (3.10a)

doe

2,2,5,6,7-Pentamethyloctane (3.10d)

5

sate

Dt : 2-Methylpentane (3.10b)

de

2,5,5-Trimethylheptane (3.10e)

oe

mee 4 . 1,2,4-Triethylcyclopentane (3.10c)

of

3-Ethyl-4-methy] hexane (3.11a)

Oe

1

4,5-Dimethyl-3-ethylheptane

(3.11b)

—_1-Ethyl-2-methylcyclohexane

(316)

4-[1,1-Dimethylethy]]5-methyloctane (3.11d)

Substitutive Nomenclature of Specific Type of Compounds

37

3.1.3 Bridged Compounds Bicyclic compounds consisting of two (or more) atoms in common are given bicyclo prefix to root name. The root name i.e., parent contains only the ring carbons. 8 1

1

wh

\

4

5

Bicyclo[2.2.0]hexane (3.12a)

Bicyclo[3.2.1]octane (3.12b)

1,7,7-Trimethylbicyclo[2.2.1]heptane (3.12c) O 5

2 2

Bicyclo[2.2.2Joctan-2-one (3.12d)

Bicyclo[2.2.2Joct-2-ene (3.12e)

ia

7-Chlorobicyclo[2.2.2]oct-5-en-2-one (3.125)

The number of carbons in each of the three bridges connecting the two bridgehead atoms is noted in square bracket in descending order. Numbering system in order of precedence is: (1) a bridge-head carbon is given locant 1 (11) longest bridge is covered first and so on (iii) substituent / modification is given lowest possible locant; positional preference among different substituents and modifications is as usual. Examples (3.12a)--(3.12f) illustrate different aspects of naming of the bridged compounds. For naming bridged compounds having heteroatoms in skeleton see section 4.1 (Replacement nomenclature).

3.1.4 Bridged Cyclic Systems with more Rings Bridged cyclic systems having more rings (four and above) are given tricyclo-, tetracyclo- etc. prefix; the parents contain the total number of skeletal atoms (including heteroatom(s), if any, specified by replacement operation as usual). The main bridge (with its two bridge atoms,

shown here in bold numbers; one is given locant viz. 1) is selected first: it is the longest bridge and divides the main ring (the largest one) into two equal (or nearly so as far as possible) rings. The additional or secondary bridges are cited in length by putting their numbers of atoms (in descending order if several secondary bridges are present). Two superscript numbers (in ascending order) indicate the location of the respective bridge. The numbers are written within the parenthesis. The following are illustrative examples:

38 Nomenclature of Organic Compounds 1

9 S

11

5 11

9

7

Tetracyclo[6.5.1.1'°0°"Jpenta-

Tricyclo[7.4.1.0°”]tetradecane

3

3

1

—_Tricylo[1.1.0.0°“]butane

decane

5

| 1

2

1

1 3

5 7

Tricyclo[3.3.1.1°"]-decane

6

2

7 5

— Pentacyclo[4.2.0.07°.0°*.0*’]-___-

(Adamantane)

octane (Cubane)

4

Tetracyclo[2.2.0.0°°.0°*)hexane (Prismane)

3.1.5 Spiro Compounds When a single carbon (or any other atom) is the common member of the two rings, the compounds are called spiro compounds. Monospiro compounds are given spiro prefix to root name that consists of total ring carbons; the number of atoms (excluding the spiro-atom) in each ring is written in bracket in ascending order. The numbering starts from the atom, next to spiro-atom, of the smaller ring and continues consecutively (in the process the spiro-atom gets lowest locant but not 1). Compounds (3.13a), (3.13b) and (3.13c) are three representative examples:

Sins

a

3 4

Spiro[3,3]heptane (3.13a)

4 5

O

Spiro[3,4]octan-5-one (3.13b)

ic

; 3

Spiro[3,4]hept-5-ene (3.13c)

3.1.6 Ring Assemblies Two or more identical cyclic systems are joined directly to each other by single or double bonds but the number of ring junction is one less than the number of cyclic systems in such category of compounds. Assemblies of two identical rings are named using prefix bi- to corresponding substituent group (additive name) or to parent hydride name (conjunctive

Substitutive Nomenclature of Specific Type of Compounds

39

operation). A parenthesis for the group or the hydride name is given, if required (see examples 3.14a — 3.14c):

Sate

1,1 -Bi(cyclopropyl)

3,4 -Bipyridyl

1,1 -Bi(cyclopenta-2,4-dien-

1,1 -Bi(cyclopropane) (3.14a)

3,4 -Bipyridine (3.14b)

1-ylidene)

(3.14c)

Assemblies of more than two unbranched identical rings are similarly named using appropriate numerical prefix ter-, quarter-, quinque-, etc. to corresponding parent hydride name (as an exception pheny] is used in preference to hydride name, benzene) (see examples 3.19a—3:15c):

CHORE 11

3! 1"

1,13;1 "-Tercyclobutane (3.15a)

(OATS LE

NEES a

ee

1,141 "-Terpheny] (3.15b)

2,2:6,2 :6 ,2 -Quaterpyridine (B-1.5c)

Dissimilar ring assemblies are named with usual substitutive nomenclature system of parent and substituent (see examples 3.16a — 3.16c):

ox 2-Phenylnaphthalene (3.16a)

OO Phenylcycloheptane (3.16b)

Ose Cylopenty!cyclohexane (3.16c)

3.1.7 Cyclophanes Cyclophanes are a class of cyclic compounds in which one or more aromatic rings (arenes) are present as bivalent substituents. The methods of their naming, in developing stage, treat each arene as a single atom (“‘superatom’) and named by replacement (skeletal) operation; the

suffix is changed to ‘-phane’. The two compounds, A and B are illustrative examples. As shown (example A) the point of attachment of bivalent arenes are written within parenthesis and locant for substituent at any arene is cited as superscript to the respective locant of the ‘superatom’. The method can be extended to linear molecules in which arenas are ‘incorporated’ into acyclic chain too (example C).

40 Nomenclature of Organic Compounds

o Sie op 9a OANOQ & “a

1*

* 6

igs fee)

1°,2-Dimethyl-1,6(1,4)dibenzenacyclodecaphane

(A)

I

2

T

sie“i 5

/

kb

;

7

_1,5(1,4)-Dinaphthalena-3,7 (1,3)-dibenzenacyclooctaphane

\

/

\

/

i

5

“V7

.

\

Us

1,14(1),4,6,9,11(1,4)Hexabenzenatetradecaphane

(B)

(C)

3.2 SATURATED COMPOUNDS HAVING ONLY THOSE CHARACTERISTIC GROUPS THAT ARE ALWAYS CITED AS PREFIX IN SUBSTUTUTIVE NOMENCLATURE 3.2.1 Ethers, Halides, Azo-, Nitro- and Nitrosocompounds, Azides 3.2.1a For simple compounds,

the parent hydride name

(including the suffix —'ane’)

remains unaltered. All these groups are shown as prefixes, very much like the alkyl / cycloalkyl / aryl substituents, to the parent hydride name; and are arranged alphabetically, when there are more than one substituents, as usual. The question of parent selection and numbering do not arise in examples, 3.17a —3.17h.

CH;I Iodomethane (3M fa}

C,H;-N=N-C,H;

Azobenzene (3.1 7e)

CH;CH,NO, Nitroethane (3.17b)

CH2N;>

Diazomethane (3.17f)

C.H;NO Nitrosobenzene G.17c)

CH;-O-CH,

Methoxymethane (3.17g)

CHCl, Trichloromethane (3.17d)

[ 1,4-Epoxybutane (3.17h)

3.2.1a Choice of parent, if necessitates, will be made in successive considera tion of the rules (3) & (8) — (10) cited in section 2.3.1. Numbering the parent chain to assign locant to the substituents will be decided by making use of the rules (i), (vii) and (viii) (section 3.5).

Examples (3.18a) — (3.18k) are illustrative of parent selection on the basis of maximum chain length (rule 3):

Substitutive Nomenclature of Specific Type of Compounds 41 Cl ee

On.

pees

Methoxyethane (3.18a) Br

2-Ethylsulfanylpropane (3.18b)

we

3-Chloromethylpentane (3.18c)

oe

;

OEt

:

ee

OMe

OEt 1-[2-Bromocyclopropyl]2-ethoxybutane (3.18d)

1

Ethoxybenzene

(3.18e)

1-Fluoro-4-[2-methoxy ethyl|cyclohexane (3.18f)

O

7

ap O a

¢ 6)

( )-ortHch,

O 1-Phenoxyheptane (3.18g)

O

ee

1,2-Methylenedioxybenzene (3.18h)

A

1

2,5-Epoxyhexane

:

3-Methyl-1,4 —epoxypentane

; Cyclopentyloxybenzene

(3.181)

(3.18k)

(3.18)) Application

O

1,4-Epoxypentane (3.181)

of parent selection

rule (8) (maximum

substituents

in the chain) are

exemplified by naming of compounds (3.19a) — (3.19c):

Koki ey 1-Chloro-3-cyclopropylpropane (3.19a)

eS

1-Chloro-2-ethoxyethane (3.19b)

1-Chloro-3-[2-methoxyethy]]2-nitrohexane (3.196)

Parent selection is decided with use of rule (9) (lowest locant for all substituents) in

examples (3.20a) and (3.20b); and the same is ascertained ultimately using rule (10) (parent to contain first cited substituent) in compound (3.21).

3.2.1b Numbering pattern will be decided mostly by numbering rules (i) [fixed numbering], (vii) [lowest locants for substituents — decision at the first point of difference] and (viii)

42 Nomenclature of Organic Compounds 1

Br

7

|

2 “Br

5 pie

ine

oot 2

3

1-Isopropoxypropane (not, 2-propoxypropane)

‘Saas

Orery

‘

ry :

5-Bromo-2-chloro-4-[2chloropropyl]heptane

2-Bromo-4-[2-chloropropy]]5-methylheptane

(not, 4-[1-Bromopropyl]-2,6dichloro-heptane)

(not, 4-[2-Bromopropyl]-2-chloro -5-methylheptane)

(3.20a)

(3.20b)

(3.21)

[alphabetical preference]. The following examples (3.22a, 3.22b and 3.23a — 3.23g) show application of one or more of these rules:

Br

OMe

ioe

NO

1

:

5

Cl

1-Methoxy-7-bromonaphthalene

3-Chloro-2-nitropentane

2F

(3.23b)

meres

|

3

3-Ethyl-4-iodohexane (3.23e)

“2NO,

2-Chloro-3-nitrobutane

(3.22b)

(3.23a) é

F

1 Br 1-Bromo-2-fluorobenzene

eee

(not, 3-Chloro-2-nitrobutane)

(3.22a)

(ie

| Fae

‘ MeO’ 5 1 “Cl 1-Chloro-3-fluoro-5methoxycyclohexane (3,236)

Aes 4

CHCl, 3-Dichloromethyl-4-ethylhexane (3.23f)

Cl Br 2 2-Bromo-6-chloroanthracene

(3.23d)

O

eh Se, 1-Chloro-2,3-epoxypropane (3.23g)

3.2.1¢ For naming of compounds having both cyclic and acyclic chains parent selection

rule- (8) [maximum substituents] supersedes rule-(3) [maximum chain length] (vide examples 3.24a — 3.24e),.

Substitutive

Nomenclature of Specific Type of Compounds

43

Br

PhCHN,

Ph

Phenyldiazomethane (3.24a)

1-Chloro-2-butylcyclopropane (3.24b)

cl

aap

Cla

1-Chloro-2-methoxy-3-cyclohexylpropane Freons’

ae

Cl

| ,

—_1,1,1-Trichloro-2,2-bis[4-chlorophenyl]ethane

(3.24d) #

2-Bromo-1,2-diphenylpropane (3.24c)

(3.24e)

(known as D.D.T)

are popular trade names of some chlorofluorocarbons.

Halides, azides, ethers and thioethers can be named by Functional class nomenclature system (see section 4.2.1), but these names are in general discouraged.

3.2.1d Additive and Common

Names:

Some halides and cyclic ethers are named by

additive system. Though these are also not preferred, a few names (3.25a — 3.25g) given are being widely used (see Table 3.1). A perhalo- prefix is used when all H of parent are substituted by the same kind of halogen; (e.g., 3.26): CF;(CF,);CF;

:

Perfluoropentane

(3.26) A few common names of halogenated compounds (3.27a—3.27c) are retained by IUPAC in addition to recommended substitutive names (the latter within parenthesis): :CCl Dichlorocarbene (Dichloromethene) (3.27a)

COC], Phosgene (3.27b)

CHX; Haloform (X = Cl, Chloroform; X = I, Iodoform; etc.) (Trihalomethane; X=Cl, Trichloromethane, etc.) (3.27c)

*Freons: A group of fluorocarbons, most of which also contain chorine, are widely used as dispersing agents in aerosol sprayers & as refrigerants in air conditioners. These are given trade name ‘freons’ by Du Pont Co. (Some other companies sold these in other names, e.g., isotron / genetron / ucon using different code names). The freon code numbers indicate the number of fluorines (no, at the

right), hydrogens (one more than the second digit), and carbons (one less than the third (left) digit; this digit is absent if there is only one carbon.). See examples (3.30a—3.30d): CF,Cly CFC CICF,CF,Cl CHF,Cl Freon 12

Freon 11

(3.30a)

(3.30b)

Freon

114

(3.30c)

Freon 22

(3.30d)

44 Nomenclature of Organic Compounds

Table 3.1: Halides and Cyclic Ethers with Additive Names

CH.Cl

gure

(3.25a)

Additive name

Substitutive name

Methylene(di)chloride

Dichloromethane

CHBT

6.256)

Ethylene dibromide

1,2-Dibromoethane

PhCHCICHCIPh

3.25¢) eye

Stilbene dichloride

1,2-Dichloro-1,2diphenylethane

(3.25d)

Carbon tetrachloride

BrCH,CH,Br

Tetrachloromethane

1-Phenyl-1,2-epoxyethane

Azo-compounds

(having —N=N-)

Ethylene oxide

Epoxyethane

Tetrahydrofuran

1,4-Epoxybutane

are named

in substitutive system as derivatives of

diazene (see section 3.5.3a).

3.2.2 Acetals and Ketals Acetals and ketals are conveniently named

in the same

manner

as ethers; these bear two

alkoxy / aryloxy groups at the same position of parent (examples 3.28a—3.28c): OMe

CH,CH,CH—OMe 1,1-Dimethoxypropane (3.28a)

MeO_

H.C

’

(OMe

Che

e-

OEt

2-Ethoxy-2-methoxypropane — 1-Ethoxy-1-phenoxycyclohexane (3.28b) (3.28c)

3.2.2a Cyclic acetals and ketals (those derived from diols and aldehydes or ketones) are better named as heterocycles (see section 4.3). These can also be named replacement to aldehydes and ketones (see section 4.2.2).

as functional

3.2.3 Crown Ethers A group of symmetrical macrocyclic polyethers are important in solvating cations. These have a general formula -(O-CH;-CH)), - [i.e., condensation polymers of ethylene glycol] and are

Substitutive Nomenclature of Specific Type of Compounds 45 named as crown ethers (by Pederson). A few examples are cited (3.29a —3.29c) to illustrate their nomenclature system (IUPAC, short names by Pederson and notation).

re

.

cow

2

1,4,7,10-Tetraoxa-

|

pete

ee 1,4,7,10, 13-Pentaoxa-

La

p/

1,4,7,10,13,16-Hexaoxa-

cyclododecane cyclopentadecane cyclooctadecane Pederson: 12-Crown-4 15-Crown-5 18-Crown-6 Notation: [12]C-4 [15]C-5 [18]C-6 (3.29a) (3.29b) (3.29c) The TUPAC system just introduces replacement operation in the cyclic hydrocarbon names. In Pederson system the first number indicates total atoms in the ring (carbon + heteroatom), the number at the end indicates number of oxygen. For naming more complex crown ethers, azacrowns and cryptands see Appendix-VII.

3.2.4 Polyethers and Polysulfides These (and mixed types) are usually named by Replacement nomenclature (section 4.1), since such names are considerably simpler than substitutive names in these cases.

3.3 UNSATURATED COMPOUNDS WITH OR WITHOUT FUNCTIONAL GROUPS WHICH ARE CITED AS PREFIX 3.3.1 Unsaturated Ethers, Halogenocompounds, etc. The generic name for these compounds would be alkene / alkyne / alkenyne / alkadiene / alkadiyne, etc. The suffix —‘ene’ and / -‘yne’ are introduced as substitutive modification to — ‘ane’ in the parent; and when required multiplicative prefix di-, tri-, etc. are to be used. 3.3.1a The parent selection, if required, would be made in successive consideration of the parent selection rules (2) — (4), (6) — (10) (section 2.3.1). That is, -‘ene’ and -‘yne’ is given

precedence over chain length and other characteristic groups having no suffix name

in

substitutive nomenclature. The same norm (section 3.5) is also followed in numbering the

parent chain; rules (vi) — (viii) are considered successively. Examples (3.31a—3.31h) where parent chain is selected by rule (2) - chain to include maximum multiple bonds:

Se

©

2-Ethylbut-1-ene (3.31a)

Phenylethene (3.31b)

Ren,

3-Propylhex-1-yne (3.31c)

46 Nomenclature of Organic Compounds

ss i

3

1-Cyclohexylpropyne

5

os

3

3-Propylpent- 1-en-4-yne

(3.31e)

(3.31d)

43

5-[Pent-4-enyl]nona-1 ,3diene-6,8-diyne (3.31f)

| Na

(

eamelig| il

3-Cyclohexylideneprop-1-ene (3.31g) Examples (3.32a—3.32d) length:

Cl

Br

2-[1-Bromo-3-chloropropyl ]buta-1,3-diene (3.31h)

where parent choice is decided at rule (3)-maximum

Y

ri3

1

OMe

1-[Prop-1-enyl]cyclohexene (3.32b)

Methylidenecyclohexane (or, Methylenecyclohexane) (3.32a)

pt

4.2273

4-(2-Methoxyetheny]]hepta-2,5-diene (3.32c)

chain

babe

3-Ethenylhex-1-en-4-yne

(3.32d)

Parent selection is decided ultimately by rule (4)[chain to include maximum number of double rather than triple bond] in examples (3.33a) and (3.33b), with the help of rule (6){lowest locant for multiple bonds] in example (3.34), and applying rule (7)[lowest locant for double rather than triple bond] in example (3.os

Zee5

3

3-Ethynylhexa-1,5-diene

(3.33a)

Li

a

4-[1-Mehylprop-2- er hepta-1,4-diene (3.33b)

Cl.

2 SX ee

UCI

4-|Prop-2-ynyl]-hept-1-en5-yne (3.34)

Br worm a Oe s 4

Cla4

5-[But-3-en-l-yn-l-yl]nona1,3,6-trien-8-yne

(3:35)

_1,4-Dichloro-3-[2-chloroethenyl]penta-1,4-diene

(3.36)

Cl

1-Bromo-4-chloro-3-[2-chloroethenyl]penta-1,4-diene

(3:37)

Substitutive Nomenclature of Specific Type of Compounds 47 Characteristic groups, shown as prefix, decides parent chain selection in examples (3.36) [lowest locant for these groups] and (3.37) [lowest locant for first cited substituent].

3.3.1b The numbering of the parent chain i.c., assigning locant to various substituents and substitutive modifications is done mostly applying numbering rules (vi) — (viii). In addition to examples discussed above a few more illustrations, indicating the particular-rule that becomes decisive, are given bellow. Numbering of compounds (3.38a) — (3.38f) is decided with rule (vi)[lowest locant for multiple bonds], that of compounds (3.39a) — (3.39c) with rule (vii) [lowest locant for substituents], and that of compounds (3.40a) — (3.40c) is

finally settled with the help rule (viii)[lowest locant for double rather than triple bond].

2

gic

MeO

1-Butene (3.38a)

oN

——

6-Methoxyhex-2-yne (3.38b)

{

a

Br

3-Bromo-3-ethylcyclopentene (3.38c)

1

plecoas 4

ZA

ee

cable =

Hex-1-en-4-yne

(3.38d)

ake 3-Methylhexa-1,5-diene (3.39a)

3

Hept-5-en-1-yne

(3.38e)

INS

Bory

3-Chlorohex-5-en-1-yne (3.39b)

AN

fo Ge

ZA

ae 4

Pent-1-en-4-yne (3.40a)

( )—sMe 5-Methylsulfanylcyclohexa1,3-diene (3.38f)

€ ;

3-Ethoxycyclohexene (3.39c)

Et

Cl 2-Chloro-5-methylhex-3-ene (3.40b)

OEt

OP

4-Ethoxyhept-1-en-6-yne (3.40c)

3.4 COMPOUNDS HAVING ONE KIND OF PRINCIPAL CHARACTERISTIC GROUPS TO BE CITED AS SUFFIX The suffix name (see Table 2.9) of the principal group along with appropriate multiplicative prefix, if two or more in number are present, is added to the parent hydride name. Only the

48 Nomenclature of Organic Compounds EE nn eR ee Fee terminal ‘e’ of hydride is elided when a vowel follows the name. Ail of this kind of groups (or at least maximum in number) is included in the parent [parent selection rule (1)]. Other substituents and substitutive modifications (-‘ene’ / -‘yne’) are considered next [rules (2) —

(10)] in choosing the parent in compounds with branched skeleton. In numbering the parent chain, too, the principal group(s), -‘ene’ /-‘yne’, and other substituents are considered in decreasing order of preference [numbering rules (i) — (viil)]. Examples are discussed with each ‘related’ class of compounds. Any special naming within substitutive system is also discussed in respective section.

3.4.1 Amines and Imines (i) Generic names would be alkanamine and alkanimine respectively. (ii) However, in an alternative nomenclature (these names are *marked), -‘amine’ is

also added substitutively to alkyl (or alkylidene in case of imine) without space (unlike functional class name). (iii) In a third type of naming, alkyl group(s) (or alkylidene in case of imine) can be

shown as prefix(es) to azane (recommended name of ammonia); just the term azane will replace amine in second type name. These names are not presented here. Examples (3.41a—3.41m) are given where all these three types of nomenclature can be applied:

NH, Propan-1-amine Propylamine* (3.41a) NH,

-sulfonate Derived by loss of | Suffix —‘ol’/ -‘thiol’ is changed to —‘olate’/ H* from alcohol /

thiol

thiolat -‘thiola te’e

CH3CH,COO_ : Propanoate (06

: Cyclohexane carboxylate

= ( \-s0; : Benzene sulfonate

CH3CH,S” : Ethane thiolate

" of

Derived by adding | Suffix —‘uide’ is added to the H

: dianion Cycloocta-2,5,7-trieny|

—p

-sulfonic acid

group group”

Example(s) _: Methanide or, Methyl anion

to neutral parent | name of hydride

\oy

: Benzene-1,4-diolate

Se

(CH3)4B :

hydride

:

amethylboranuide

Fig. 3.6 *These are actually salts of acids; see also sections-3.4.6, 3.4.6b, 3.4.6c "These are salts of alcohols, phenols and their thio--analogues; see also section-3.4.2b

Substitutive Nomenclature of Specific Type of Compounds Name modification

Derived by removing one H from a parent hydride

Suffix —‘ylium’ to replace-‘ane’(or —‘yl’ of

Or, by loss of one &

A class name ‘cation’ is written as a separate word following the radical name. Appropriate multiplying prefixes for polycations.

from a radical

Acyl Cation: Derived formally by expelling HO from an acid

Or, formally loss of one e from acyl radical

radical name)

of H’ at any position

CH3CH2CH2* : Propylium; Propyl cation 1-Methylpropyl cation (or, Butan-2-yl cation)

*CHoCHp"* : Ethan-1,2-bis(ylium); Ethan-1 ,2-diyl dication hah : Cyclobut-3-en-1 ,2-bis(ylium); + _Cyclobut-3-ene-1,2-diyl dication

Suffix —‘ylium’ to replace —‘ic acid’ ending

HCO?

of acid name (or,

cabonylium for carboxylic acid) ‘Cation’ is written as a separate word following

: Formylium; Formyl / Methanoyl cation

C,H ;CO* : Benzoylium; Benzoyl Cation

the name of acyl group

added to element name

H,0* : Oxonium;

Et3O*: Triethyloxonium

H,P* : Phosphonium

hydride of O, N, S, P,

halogen having unshared pair of e and standard bonding number Derived by addition

Example(s)

CH3CHeHC*CHs: 1-Methylpropylium;

Derived by adding H* Suffix name —‘onium’ is to mononuclear

71

Substituents are denoted

as prefixes as usual

H,N* : Ammonium # ; BuyN* : Tetrabutylammonium

Suffix —‘ium’ is added to parent hydride name

CH

: Benzenium

\

: Prydin-1-ium

(to indicate with

locant if not unambiguous) of a neutral parent hydride

ese

Fig. 3.7

*an exception (not azonium; nitronium is not recommended due to familiarity of NO,” by this name). However, HN," is given the name diazonium and diazonium salts (3.81a and 3.81b) are so named

(seniority of —‘onium’ over other functional group is maintained, where needed):

( \-ten cIBenzenediazonium chloride

(3.81a)

Hos—(_\

en BFa

4-Sulfobenzenediazonium fluoroborate

(3.81b)

72 Nomenclature of Organic Compounds Name modification

Example(s)

Derived by removal of one H from mononuclear parent hydride of any group IV element}

Suffix —‘yl’ to replace -‘ane’ of the compound name

CH3CHsCH2CH, : Butyl

or, from the terminal of

(Looks like alkyl,

unbranched satd. hydrocarbon

| alkenyl/alkynyl sroups)

Derived by removal of one H from any other parent hydride, other element or any branched and / or unsaturated hydrocarbon

Suffix —‘yl’ to be added to parent name

Bivalent radicals derived by

Common names

Cc ; ‘pa : 2-Methylcyclobutan-1-yl >:

: Cyclopent-2-en-1-yl

HN : Azanyl (Amino#) CH2 or ‘CH.

: Methylene (or, Carbene)

NH

:Nitrene

removal of two H from CHg,

NH, SiH,, etc.

Bivalent (or tervalent) radicals

| Suffix —‘ylidene’

CH,CH or

derived by removal of two H (or| (or, three H) from same skeletal -‘ylidyne’) to be atom of any other parent hydride! added to parent name

Multivalent radicals:

Ch3CH

: Ethylidene

CH)CHCH,

Appropriate multiplying affixes

separate radical centers

or-NH_

CHj3CHCH _ : Propan-1-ylidene-2-yl

are used

“CHCH2CH

Suffix —‘yl’ (or carbonyl) to replace

Acyl radicals derived by removing OH (all, if there are more than one) from acid

: Propane-1,2,3-triyl

: Propane-1,3-diylidene

CH3;CO-_

Ethanoyl / Acetyl

‘ic acid’ (or

: Phthaloy!

carboxylic acid) ending of the acid name

: Cyclobutancarbony!|

Fig. 3.8 #

Re

HOw:

ns

Traditional name; hydroxyl ( ) is also accepted traditional name. *Derivatives are named by showing substituent prefixes e.g.,

Ph,C/Ph,C-

: Diphenylmethylene;

CH3zCON:

:Acetyl nitrene

Substitutive Nomenclature of Specific Type of Compounds

73

The compounds with both cationic and anionic centers are called zwitter ions. In naming these seniority of anion over cation is maintained. Thus cation is introduced as prefix (-‘onium’

and -‘ium’ are changed to —‘onio’ and -‘io’ respectively) to anion name or anion is introduced as suffix in the cation name. Examples are given bellow:

(CHg)3N°CH,CO,

Hg NX

Trimethyl ammonio acetate

007

4-Ammoniobenzene-1-carboxylate

(3.82a)

(3.82b)

\ N-89s Pyridin-1-ium sulfonate (3.82c).

3.6 COMPOUNDS HAVING AT LEAST TWO DIFFERENT CHARACTRISTIC GROUPS THAT ARE CITED AS SUFFIX To name such compounds by substitutive system the senior-most group is to be decided. This is to be called the principal group. Maximum numbers of this principal group are to be included in parent. See examples 2.4a—2.4e for illustration. The other characteristic group(s) (that are cited as suffix when present alone / being the senior-most) is / are treated now at par with those groups which are always placed as prefix. Thus these groups become less important than carbon-carbon double and triple bonds (and also primary substituent; these may be also primary substituents) in selecting parent or in deciding numbering of the parent. See examples 3.90, 3.91, example (xii) in Fig. 3.9 and example (xi) in Fig. 3.10. Even the principal group that falls outside the parent is cited as prefix (secondary) and cannot ‘enjoy’ seniority in selecting primary substituent and it’s numbering. See example (xvii) in Fig 3.10.

3.7 SYSTEMATIC APPROACHES TO NAME A COMPOUND BY SUBSTUTUTIVE NOMENCLATURE Different types of compounds are dealt with in this section; the derivation of the complete name is shown step by step. Bold letters indicates principal group. For better understanding the diagrammatic sketches in section 2.2.1 may be consulted. Example 3.83:

Substituents to be cited as prefix:

Characteristic g Parent (subtractive modification due to C=C;

numbering included) + suffix due to principal group -OH

Hydroxy-

-CH;

Methyl-

Nev

MEO oe

SOH Complete name: 3-Hydroxy -4-methylpent-4-en-1-al

pent-4-en-1

-al

74 Nomenclature of Organic Compounds

Example 3.84:

HO,C

BRL OON((CH,) »Br

CH, Ph

Characteristic groups: -CO2H, -N*Br° Substituents to be cited as prefix:

-CH;Ph

“CH,CH;CO,H -CO.H

CarboxyBenzyl-

Fa ig

Parent hydride and anion (suffix)

ete H,N Br

CH;CH,-

-ammonium bromide

Ethyl2-Carboxyethyl-

ae =

Full name: Benzyl-2-carboxyethyldimethylammonium bromide

Example 3.85:

Substituents to be cited as prefix:

Characteristic groups: -Cl, -Br, >C=O Parent (including modification due to C=C

-C]

Chloro-}|

-Br

Bromo-

-CH2CH;

ethyl

-CH,CH;

&

incomplete*

numbering)

Suffix

ethyl

Las

Tien

O nona-3,6-dien-5-one

Complete name: 8-Bromo-1-chloro-4,6-diethyInona-3,6-dien-1-one

*Complete numbering is decided here by other substituents.

ee

+

Substitutive Nomenclature of Specific Type of Compounds

75

Example 3.86:

Characteristic groups:

Substituents to be cited as prefix: “Cl -CH,CHLOH “"NHCH; Sec. sub oa) Prim: subs)

-OH

Sec;

Prim.

-CH,CH; | -CH; | -NH,

Chl-| Hydroxy- | Ethyloro-| 2-HydroxyethylBr

hal

Methyl-|AminoMethylaminor

H 7

atk 2: bras ee

i

OH tridecan-3,10-diol

| 13

10 OH

-OH, -Br, -Cl, -NH-

Parent + principal groups included in it, with numbering of the parent:

NHCH

Characteristic groups: -SH, -Br, -Cl, -OH, -NHParent (with

numbering) - + principal group: H

Cl

6

-CH; Chloro-

| -NH)

methyl- | amino-

~.

OH

NHCH,

1 -nonan-1,6-diol

Full name: 8- Chloro-3-[1,3-dibromo-4-sulfanylhexy]]-7-methylaminononane-1,6-diol

76 Nomenclature of Organic Compounds Example 3.88:

-Br

-OC,H;

Bromo-

Ethoxy-

Alcohol part:

Ce 3" 1’-Methylpropyl-

Ch. grs:

>C=O, -NH2, -COO-(alkyl) [ester]

Subst. (prefix) to parent: (>C)=O

OxoAlcohol part:

-CH,NH,

Parent (numbering & mod. for C=C included) + suffix:

“NH, ..|-CH;

se

Amino- | methylAminomethy]-

O -pent-2-en-1-oate

Parent with all its substituents and modifications: Ph

Osan > |_l’-Methyl-2’-phenylpropy!-

| Complete name: 1’-Methyl-2’-phenylpropyl 2-aminomethyl

pent-2-en-1-oate

Substitutive Nomenclature of Specific Type of Compounds

77

Example 3.90: O

wenoo—(_\)—o-LL ouch-ch, CH,CH,CH,OH Charact.

groups: -N-CO- [amide], -OCO- [ester], -OH

Sub. to be cited as prefix to |Parent with subtractive mod. parent: | -CH,CH,CH,OH |Numbering + principal ch. gr:

Sec. sub. | Prim. sub. -OH Hydroxy-

O 3 2 Pe Oe alba! CHCH=CH, 4

©

CH;CH,CH>Propyl-

-but-3-en-1-oate

3-Hydroxypropyl| Parent part (viz., acid portion) with its substituent prefix: O 3

Alcohol part:

--o—l_CHCH=CH,

Yo)

wewwoo

Dimethylcarbamoy]]

Rneeneg yet

aa AP phenyl-

wenoo

-2-[3-hydroxypropylbut-3-en-1-oate

Q gion, \--o-londu.ch, = CH,CH,CH,OH

Full name: 4’-[N,N-Dimethylcarbamoyl]phenyl

2-[3-hydroxypropyl]but-3-en-1-oate

© wenoc—(_\\Io-cuoH.oH, CH,CH,CH,

Example 3.91:

haracteristic eroups: -N-CO- [amide], -CO-Q-(alkyl) [ester]

Substituent to parent: Me,NHCO-

Me, Me

Dimethyl-

-CONH,

carbamoyl-

N,N-Dimethylcarbamoy]Parent (viz., acid) part including its prefix:

Alcohol part: iW

Parent with numbering + principal characteristic group:

3

(0)—CHCH=CH, CH,CH,CH, 1’-Propylprop-2’-eny]l-

Me,woc-/

-benzoate

Q \)1-Il_o...

- 4-N, N-dimethylcarbamoylbenzoate

9—;7$——s weno"! -L_9—CHCH=CH, CH,CH,CH,

Complete name: 1’-Propylprop-2’-enyl

4-[N,N-dimethylcarbamoyl]|benzoate

78 Nomenclature of Organic Compounds Example 3.92:

prt

O

\o-gichact,

CH,CH,CH,CN Characteristic

groups:

-HN-CO- [amide],

Substituents to be cited as prefix: 1

Parent with numbering + suffix for principal group:

3

(0)—CHCH=CH, CH,CH,CH,CN

Ph-

-CN CH,CH2CH; cyano- | propyl3 1

—CH,CH,CH,CN

O

= |(O)~CHCH=CH,

3-cyanopropyl-

Phenyl-

ern

o

3

1

prop-2-enoxy-

1-[3-cyanopropyl]prop-2-enoxyor, 6-Cyanohex-1-en-3-yloxy-

-benzamide

\o-ghctac, CH,CH,CH,CN

Complete name: N-Phenyl-4-[1-(3-cyanopropyl)prop-2-enoxy ]benzamide or, 4-[6-Cyanohex-1-en-3-yloxy]-N-phenylbenzamide

Example 3.93: Hoe)

CO,H 2

OH Characteristic groups:

-OH, -COOH

Substituents to be cited as prefix: Parent with suffix and

numbering: DP

Hydroxy-

Complete name: 6-[4-Carboxycyclohexyl]-6-hydroxyhexanoic acid

ah

eo

--hexanoic acid

Substitutive Nomenclature of Specific Type of Compounds

79

Example 3.94;

SOE®

OH

Cl

Primary substituent:

Parent with Suffix & | numbering:

2-Ethoxyethy]Total substituent:

2-[3-Amino-1-methylpropyl]-4-[2-chloropropyl]-5-[2-

-ethanol

ethoxyethyl]cyclohexyl-

Complete name: 2-[2-(3- Amino-1-methylpropyl)-4-(2-chloropropyl)-5-(2-

ethoxyethyl)cyclohexyl]ethanol Or, 2-[2-(4-Aminobutan-2-yl)-4-(2-chloropropan-1-yl)-5-(2-ethoxyethyl) cyclohexanyl]ethan-1-ol

80 Nomenclature of Organic Compounds

3.8 FUNCTIONALITY VARIATION WITH SAME SKELETON The examples in Fig. 3.9 illustrate the how parent selection changes (or does not change; note examples (x) and (xx); (ix) and (xvii); (xv) and (xvi) with introduction of various characteristic

(functional) groups, the skeleton in different examples remaining same or nearly so.

Examples (Structure and Name)

Examples (Structure and Name)

\ at7

4

NG

4-Ethenyl-4-methylocta-7-en-1

-yne

HO-3 "Sou

S (vi)

2-Butyl-2-[prop-2-ynyl]butan- 1 ,4-diol HO -

OH OH

2-Propyl]-2-[2-sulfanylbut-3-enyl]butan-1,4-diol

3-Butyl-3-hydroxymethylhexane-1 ,6-diol (vii)

(vill) HO 6

OH

1 COOH

2-[2-Hydroxyethyl]-2-hydroxymethyloctane-1 ,8-diol

(ix)

2-[2-Hydroxyethyl]-2-[3-hydroxypropyl]-

(x)

hexanoic acid

aX 6

O

4COOH

OH

2-Formylmethyl-2-[3-hydroxypropyl]yime 2-[3-Hydroxypropy]]-2-[2-oxobuty]]hexanoic acid (xi) | but-3-en-1-oic acid (xii) Fig. 3.9 contd...next page

Substitutive HOOC 4

Nomenclature of Specific Type of Compounds 81

:

HOOC

Pe O

4,COOH

GOOH

COOH

2-[3-Hydroxypropyl]-2-[2-oxobutyl]butane-1,4-dioic acid

2-Butylbutane-1,2,4- tricarboxylic acid (xiii)

(xiv)

HOOC AGA, COOH

poor

COOH pate

HOOCe

COOH

COOH

3-Carboxymethylhexane-1,3,6-tricar-

boxylic acid

,

__Hooc YS

Hood

Hexane-1,3,3,6-tetracarboxylic acid

(xv)

HOOC.

COOH

COOH

Baee

COOH

COOH

3,3-DilcarboxymethylJoctane-1,8-

dioic acid

Hooc.4

EtO,C

CO,Et

2-[3-Carbethoxypropyl]butane-1,2,4-

tricarboxylic acid EtO,C

1COOH

2-[2-Carbethoxyethy]]-2-[3-carbethoxypropy]]butane-1,4-dioic acid

EtO,C

5

2-Carbethoxymethyl-2-[2-carbethoxy(xix) | ethyl]hexanoic acid

EtO,C

CO,Et

EASA

1COOH methyl-5-carbethoxypentanoic acid

EtO,C

(xx)

AGO 2 =

CO,Et

2-[2-Carbethoxyethyl]-2-carbethoxy-

8 EtO,C

(xviii)

CO,Et

.

1COOH

EtO,C

(xvi)

,

Ethyl 3-[carbethoxymethyl]hexane(xxi) | 1,3,6-tricarboxylate

(xxil)

)

CO,Et 1

Cl * NMe,Et

Ethyl 4-carbethoxymethyl-4-methyl octane-1,8-dioate

Br Me,NC ,

6

___ |Ethyl(1-ethyl-1-propylpentyl)dimethyl(xxiii) |ammonium chloride

ey

CO, Et

Cie ee OO

4 COOH

(2-Carbethoxyethyl-2-carboxyhexyl)

(xxiv)

[res ;

Butyl(ethyl)methyl(propyl)ammonium

|trimethylammonium bromide ___(xxv) |chloride Fig. 3.9

.

HeSHY

82 Nomenclature of Organic Compounds The examples in Fig. 3.10 illustrate the same numbering the parent and parent substituents. Examples (Structure and

4é

but draw a little more

Examples (Structure and Name)

Name)

=

;dhergeony

1-Ethyl-4-methylcyclohexane

(iii)

\,

4-Methylcyclohexylethene

(i)

1

1-Ethyl-4-methylidenecyclohexane

in

attention

(ii)

—

3-Ethenyl-6-methylcyclohexene

HO

(iv)

HO

'

e

\

[4-Ethenylcyclohex-2-enyl]methanol

w (Vv)

OH 1 5

2 \

2-Ethenyl-5-methylcyclohexanol

2 (vii)

*\1 on

2-[4-Hydroxymethylcyclohex-2-enyl]ethanol (vi) fe)

5

5-Ethyl-2-methylcyclohexanone


—CH,

———_»>

CH3CH,

CH;0

Example 3.99: 2-Bromo-3-chloro-5-[4-chloro-2-(hydroxymethyl)-5-oxohexan-3-yl]-

cyclohexanecarboxylic acid Bromo-

Chloro-|

Prefixes: 4-Chloro-2-(hydroxymethyl)-5-oxohex-3-enylSec. prefixes Prim. prefix: Chloro- |Hydroxymethyl- |Oxo- |Hex-3-enyl-Cl

HOCH)-

Parent + suffix: Cyclohexanecarboxylic acid

=O | C-C-C=C-C-C-

homO y-¢-Cate oa Cl CH,OH

«_-c00r

86 Nomenclature of Organic Compounds eT Ex. 3.100: 2-[3-Chloro-2-ethy]-1-hydroxybuty!]-5-methylamino-4-[prop-2-enyl]phenol Parent (a function-

al parent): -phenol

Prop-2-enylSec. prefixes:

Prim. prefix:

C=C-CCHs-_| NH2HO-, CoHs-, Cl- | CHsCH,CH,CH)-_| - | H,C=CH-CH,| H(OH) CH3NH-_ ,Hs)C | ICH(C [___CH,CHC CH(OH)CH(C,H,)CHCICH, Complete Structure:

2

H,C=CH-CH;—

—OH

CH,NH

5

Example 3.101: Ethyl 6-nitro-5-propylindole-2-carboxylate

Parent + suffix: -indole-2-carboxylate

Prefixes to parent chain:

Alcohol part: Ethyl- : C2Hs-

Parent part (acid) including

|

substituents attached to it:

Complete Structure:

.

-

é

5]

]

O,N’ 6 2

|

N

H

Example 3.102: 1’-Methylbutyl 6-amino-4-formylmethylhexanoate Prefixes:

Parent + suffix:

Alcohol part: 1’-Methylbutyl-

Prefixes to parent chain: Formylmethy]

Sec. sub,} Prim. sub.: Methyl- | Butyl:

Sec. sub. Formyl: OHC-

CH;-

-hexanoate

Prim. sub. Methyl]: H3C-

C--C--C--C--C--C--O6 1

-CH,CH,CH2CH3;

—CHCH,CH,CH, 3

Complete Structure:

Parent part including

substituents:

22 Yn

Boose

ae SE

Ge

ee

fe oe 2

0 H,N—CH,--CH,~GH--CH,~CH,-C-O-CHCH,CH,CH, CH,CHO

CH,

2

CHAPTER 4

Nomenclatures other

than Substitutive Type

4.1 REPLACEMENT NOMENCLATURE It is applicable when skeletal atom(s) (often C) of a parent cyclic / acyclic hydride is / are replaced by other atom(s) e.g., O, N, S, B etc. The number of H is adjusted according to the valences of the atoms concerned. The use of this nomenclature is recommended only when substitutive nomenclature becomes too complex / cumbersome’. Also this should not result in loss of ‘familiarity’ of a characteristic group*. The heteroatoms, that are placed, are denoted by respective prefix terms (often called “a” prefixes, since the names end in ‘a’ and not elided even if a vowel follows in the name). A list of common heteroatoms and their “a” prefix terms are shown in Table 4.1 in order of their decreasing priority (elements of higher group is preferred to elements of lower group, and within a group preference decreases from top to bottom). This priority order is applied in citation and hence in numbering a parent when different skeletal heteroatoms get same location from either direction (examples 4.3a and 4.3b). This priority order is also enforced in selecting a parent when principal characteristic group (maximum numbers when present more than one), number of heteroatoms, and length of chains in succession fail to settle the issue (example 4.7e).

*No limit for the number of heteroatoms or hetero units is given; but CAS restricts the minimum number to four for use of replacement skeletal naming. A hetero unit may be a single atom or a cluster that can be named by a single prefix e.g., diazeno- (-N=N-). “As for example, naming of esters, anhydrides, secondary and tertiary amines and amides could not be given such names (for examples see Appendix - V).

88 Nomenclature of Organic Compounds le a

ee

EE

re

een

Table 4.1: List of “a” Prefixes for Some Common Heteroatoms [Hantsch-

Widman] in order of decreasing priority

Od) Sd) SilaBoraThe position of each heteroatom, so placed, is indicated by an appropriate locant. In absence of any principal group(s), locant is allotted so as to give lowest number to the heteroatoms considered together (examples 4.2), and if undecided lowest number to the one cited first (the preferred one in Table 4.1; examples 4.3a and 4.3b). It is to be noted that all the skeletal atoms of the parent (now considered) are numbered.

O03

tose a 2 O 5

.a y gate 5

a

2,5,8-Trioxanonane

1,3,5-Trioxacyclohexane

(Name as an heterocycle: 1,3,5-Trioxane) (4.1b)

(4.1a) 7 8 PO

4

Sores HN4

1

H

Saree

7-Oxa-2-thia- 4-azaoctane (4.2)

:

O1

1-Oxa-4-azacyclohexane (Common name: Morpholine) (4.3a) H~p9 1

9 OO

S 6 oO

3 NGS

H 3-Oxa-6-thia-9-azaundecane

A

9-Borabicyclo[3.3.1]nonane*

(not, 3-Aza- 9-oxa-6-thiaundecane)

or, N-Ethyl-6-oxa-3-thiaoctan-1-amine

(4.3b)

other valence is indicated as superscript to A, e.g.,

2 5 8 CH3 O CH, CH PH; CH, CH, § CH; : 2-Oxa-5A°-phospha-8-thianonane "for numbering of bridged compound see section 2.3

5

(4.4)

Nomenclature other than Substitutive Type 89

If a terminal heteroatom in the parent chain constitutes a principal group, and hence cited as suffix it is not numbered i.e., not included in parent (examples 4.5a and 4.5b). A secondary (and tertiary) amine function at the end of a chain can be treated as one substituted amine function (cited as suffix) or its N can be included as skeletal atom in the parent (ex.

4.3b). The C of a terminal functional group, cited as suffix, is obviously included in parent. In any case the ‘suffixed’ characteristic groups determines the numbering the skeletal atoms i.e., these are given priority over skeletal heteroatoms (examples 4.5a—4.5c). A substituent like an alkyl / aryl / a characteristic group that is cited as prefix only, eitherin the middle or at the terminal of the chain is written as prefix as usual and are given locant without any preference (see examples 4.5c and 4.6): 1

POISON

3

Ns

6

9

Legon Nie eT

3

2,5-Dioxaheptan-7-ol (not, 3,6-Dioxaheptan-1-ol) (4.5a)

ney

11

3-Thia- 6-azanonane-1,9-diamine

(4.5b) OMe

0°

SE ee.

6 Drees COH

3

2

1 1-Hydroxy-3-methoxy-6,9-dioxaundecanoic acid (4.5c)

0°

we ao

A ost

10

Og

10-Chloro-6-methy]-2,5-dioxa-8-thianonane (4.6)

In compounds with branched skeletons containing heteroatoms principal groups are given top priority in parent selection (example 4.7a). If undecided, then the heteroatoms (maximum number: example 4.7b and 4.7c), and length of the chains (containing heteroatoms; ex.4.7d), are considered in succession. Thereafter the priority (Table 4.1) of skeletal atoms (example 4.7e) is considered. Other parent selection rules (multiple bonds etc.; example 4.7f and 4.7g) are applied successively as usual. When locants of groups are determining factor heteroatoms (example 4.8) are considered first. O

HO,C._O 10

8

6

30 22.0

oA

6-[2,5-Dioxahexy]]-2-methoxy-3,8-dioxadecane-1,10-dioic acid (4.7a)

os. Pay

S,

ee

0.

0,

O,

5-[Propoxymethy]]-2,4,6-trioxa-8-thianonane (4.7b)

Se oe

2

6-[But-2-enyl]-2,7-dioxa-5-thianonane

(4.7c)

Ses

wee

3~_ON

2

6-[Methoxymethy]]-2-oxa-5 ,8-dithiadecane (not, 6-[2-Thiabutyl]-2,8-dioxa-5-thianonane)

(4.7d)

90 Nomenclature of Organic Compounds Oxentig

Oscapre

aneesateyee

gia roamed farmer

not,5-[3-Oxabut-2-enyl]-4,7-dioxa-2-thianonane

(4.7e)

vsOg

5

79

pape

5-Ethoxymethyl-4,8-dioxa-2-thianon-6-ene

5-[Vinylsulfanyl]-3,7-dioxanonane not,4-[2-Oxabutyl]-6-oxa-3-thiaoct-l-ene

ZA

(4.7f)

~0 3 as

SritiehoO

Sie

on

aes

5-[3-Methoxypropyl]-2,7-dioxadec-3-ene 5-[2-Methoxyethyl]-4,7-dioxa-2-thianonane (not, 5-Propoxymethyl-2,9-dioxadec-3-ene) (not, 5-[Ethoxymethyl]-4,8-dioxa-2-thianonane)

(4.7g)

(4.8)

A substituent having heteroatoms (more than one) in the chain can be named replacement system, too (see example 4.7a).

by

4.2 FUNCTIONAL CLASS NOMENCLATURE 4.2.1 Radicofunctional Names Functional class term (Table 2.10) is written as a separate word following the name of the parent substituent radical(s); earlier these are called radicofunctional names. Examples

(4.9a—4.9}) are given in Fig. 4.1. In naming multifunctional compounds seniority order of class names is maintained. A decreasing order is as follows: acid halide(F, Cl, Br, I), cyanide, isocyanide, ketone, alcohol, ether/oxide, sulfide, sulfoxide, sulfone, halide(F, Cl, Br, I), azide.

The following examples (4.10a—4.10c) illustrate this point: oi

O

HOM Se a

Ono

O

2-Ethoxyethy] alcohol Ethylethoxymethy] ketone (not, Ethyl-2-hydroxyethyl ether) (not, Ethyl-2-oxobutyl ether) (4.10a) (4.10b)

cr ONS Bis-(2-chloroethyl) ether

(4.10c)

This system is generally discouraged, as the names do not have any simplification over the substitutive names.

4.2.2 Functional Modifier In another type of Functional class name the functional class term is written also as separate word to follow a parent functional name; the functional class term is a functional modifier in

Nomenclature other than Substitutive Type 91 this case. Examples (4.1 1a—4.11h) are shown in Fig. 4.2.

CHI

(4.9a)

CH3CH»,SCH>CH; (4.9b) CH3;COCH>CH;

Methyl] iodide

CH3COCI

CH3CH,CH,OH (4.9f) Ethylmethy] ketone |}} CH;SOCH3;

(4.9c)

Acetyl chloride Propyl alcohol | Dimethy] sulfoxide

(4.92 )

CH;0C(CH3)3

(4.9d) | t-Butylmeth

CH3;0

(4.91) |_Sodium methoxide | PhS K*

Na*

(4.9e)

Diethy! sulfide

1 ether || PhSO,Me

(4.9h) | Methylphenyl

sulfone

__(4.9}) | Pot. thiophenoxide

Fig. 4.1

CH,CH,CH=NOH | Propanal oxime

CH,CH(OC,H,),

Ethane

(4.11e)

diethylacetal

(4.1 1a)

PhCH=NNHCONH, | Benzaldehyde (4.11b)

(=n

CH,(CH,),CH(SCH,), (4.11f)

Cyclohexanone

PhG(OCH,)OC,H,

2

hydrazone

CH,

(4.1 1c)

| _Hexanal dimethy] dithioacetal

semicarbazone

Acetophenone

ethylmethylketal

(4.11g) Butanoic acid

CH,CH,CH,CONHNH, | hydrazide

Propanal-S-

CHCHCHIOGH)SCA; |.ethyl-Gamncthyl

(4.11d)

(4.1 1h)

monothioacetal

Fig. 4.2 Sometimes these names (4.12a--4.12d) look like additive names.

°

Diphenyldiazene oxide (4.12a)

(So 16 N—O

Pyridine-N-oxide (or, Pyridine-1-oxide)

(4.12c)

(4-Carboxyphenyl)phenyldiazene-2-oxide (4.12b)

PEPEQ Styrene oxide

(4.12d)

92 Nomenclature of Organic Compounds

4.2.2a In some cases (e.g., 4.13a and 4.13b) a functional replacement is made within this nomenclature system; e.g.,

HOG

epg

OH Ss

OH >

3

Thioacetic-O-acid

Ho

O

Acetic acid

SH O

Thioacetic-S-acid

(4.13b)

(4.13a)

4.3 HANTZSCH-WIDMAN NOMENCLATURE (FOR HETEROCYCLIC COMPOUNDS) Monocyclic compounds (including cyclic amines and cyclic ethers) with not more than 10 ring members, and containing one heteroatom are named by using the extended HantzschWidman system. A stem (see Table 4.2) is used to indicate the size of the ring. This stem is combined with ‘‘a’’-prefix (Table 4.1) for the heteroatom. Stems for saturated and unsaturated rings are different. Some examples (4.14a—4.14h) are given bellow. These also include cyclic acetals and ketals (ex. 4.14e which is a thioacetal).

H N

O Oxirane (4.14a)

Aziridine (or, Azirane) (4.14b)

S331 eee 1,3-Dithiolane

(4.14e)

Different

H N Azirene (4.14c)

O

N¢4

O

UN tN7

1,4-Dioxane

1,2,4-Triazine

(4.14f)

heteroatoms,

Oxitane (4.14d)

= \

(4.14g)

if present (e.g., examples

4.15a

N14 2

2H-Azepine

(4.14h)

and 4.15b),

are cited and

numbered in order of seniority (e.g., O is given seniority to S; N is senior to P; O and S are senior to N or P): ow

N

.a fea

(4.15a)

—

:1,3-Oxazole

ota,

|

- 2,2,2-Triphenyloxaphophetane

(4.15b)

Retained trivial and semisystematic names of some important heterocycles (4.16a— 4.16n) are given in Fig. 4.3.

Nomenclature other than Substitutive Type 93 Table 4.2: Stems for Various Rings in Hantzsch-Widman system Ring Size

Saturated Ring

Unsaturated Ring

-irene -ole

areeetardenense patie FI le ents Saale. ocane an 0 ie. ve eels -onane 0 -ecane

-epine -ocine -onine -ecine

Structure

Trivial

(b) X = NH: (c)X=

\

ag

to

S_:

NE

Pyrrole

Name

Pyrrolidine

(4.16h) (a) X=O:

Thiophene

Isooxazole (b) X = NH: Pyrazole

Imidazole

(Clee

Pyridazine

Pyrazine

(4.16k) 2H-Pyran 4H-Pyran

(4.161) ( Quinuclidine

NH

Piperidine (4.16m)

Fig. 4.3 **When the heteroatom is N, -iridine, -etidine and -olidine are often written as stems.

94 Nomenclature of Organic Compounds

4.3.1 Lactones, Lactams, Cyclic anhydrides and Cyclic imides

These can be named as derivatives of heterocycles; -‘one’ / -‘dione’ suffix (this may mislead one to treat these as ketones!) is added to corresponding heterocyclic name. One example of each class of these compounds is cited (4.17—4.20).

O eeH

Ce

(

O :

(

O

O

Tetrahydrofuran-2-one

(4.17)

5-Methylpyrroli-

Tetrahydropyran-

din-2-one

2,6-dione

(4.18)

(4.19)

v N-Me O

N-Methylpiperidine2,6-dione

(4.20)

4.4 FUSION NAMES (FOR FUSED RING COMPOUNDS) Polycyclic ring systems in which any two adjacent rings have two (and only two) adjacent atoms in common are said to be fused ring compounds (actually ortho-fused). When more than three benzene rings are fused in rectilinear arrangement suffix ‘-acene’ is used after the numerical term (example 4.21 in Fig. 4.4) denoting the number of benzene rings. Structure

Terphenylene (4.23b)

Biphenylene (4.23a)

Benzo[b]furan’ *

Benz[a]

{or simply

anthracene*

benzofuran }

(4.24a)

(4.24b)

Fig. 4.4

*the peripheral side of the parent ring is denoted by letters ‘a’, ‘b’, ‘c’, etc., starting with 1,2 as ‘a’; 2,3 as ‘b’ and so on. The common / ‘fused’ side is written within square bracket. # 5 . 4 Often heterocycle is treated as parent i.e., named as suffix. These compounds have fixed numbering.

Nomenclature other than Substitutive Type 95

When two fused monocyclic rings are identical and contain maximum possible noncumulative double bonds suffix ‘-alene’ is used after the numerical term denoting total number of carbons (example 4.22, Fig. 4.4). When a central ring has all the atoms in common with two or more phenylene groups, suffix —‘phenylene’ is used after the numerical term denoting the number of phenylene groups (examples 4.23a and 4.23b, Fig. 4.4).

Fused ring compounds, having maximum number of non-cumulative C=C and with no accepted trivial / semi systematic name, are named by selecting the principal ring (or component) to be cited as suffix and then designating the other components as prefix (examples 4.24a and 4.24b cited in Fig. 4.4).

Retained trivial and semisystematic names of some important fused ring compounds (4.25a—4.25m) are:

Naphthalene (4.25a)

Indene (4.25e)

Anthracene (4.25b)

Naphthacene (4.25c)

Phenanthrene (4.25f)

ioe

(4.25h)

oor Pyrene (4.25g)

:

(DY

bes Acenaphthylene

Azulene (4.25d)

N

Fluorene

(4.251)

Indole

(4.25)) H

oe,

ans

Y,

Quinoline

Isoquinoline

Purine

(4.25k)

(4.251)

(4.25m)

4.5 CONJUNCTIVE NOMENCLATURE This type of naming is applied to compounds having both cyclic and acyclic chains, linked directly together by removing appropriate number of H from each component, with the latter

96 Nomenclature of Organic Compounds

containing only one principal characteristic group’. More than one acyclic component may be present but only the identical ones are written by conjunctive system. The name of the parent cyclic hydride and those of the acyclic components (parent + suffix name of principal function) are written successively without elision of any letter in any case .For examples (4.26—4.26c) are given for illustration.

OH

Oana.

Cyclobutaneethanol

Cyclopentanebutanal

(4.26a)

CH,CO,H CH,CO,H Cyclohexane-1,1-diacetic acid (or, Cyclohexane-1,1-diethanoic acid)

(4.26b)

(4.26c)

The parent of an acyclic component only extends from the principal group to the carbon that is linked to the ring. Thus only locants for attachment of cyclic component are to be cited, when required. The atoms of acyclic chain are numbered by Greek letters (,B,y, etc.) starting with the C linked to the characteristic group as @; the ring atoms are numbered as usual. For illustrative examples see compounds (4.27a--4.27c).

5

inp

1X

CO,H

(|

B-Chloro-y -methyl-2-naphth-alenebutanoic acid (4.27a)

B

a OH

goo

CN

i:

Br

NC

4-Bromo-f-ethyl-a-methylcyclohexaneethanol (4.27b)

Qa

1

a”

3-Cyanomethyl-a,o -dimethyl -2,6-pyridinediethanenitrile (4.27c)

When two or more non-identical side chains are attached to a ring, only the senior side chain is named as conjunctive component, others are cited as prefixes. Illustrative Examples (4.27c, 4.28a and 4.28b) are given.

1

CO,H

4 a

-CHO

4

ral 3

3

3-Carboxymethylbenzenepropanoic acid (4.28a)

#

:

1 HO oC CHs

CHO

CH,CO>H

-Chloro-3-formylmethylcyclohexanepropanal (4.28b)

Ae

CO>H

2

CH,CO,H 4-[2-Carboxyethyl]benzene1,2-diacetic acid (4.28c)

. A . As if two (or more) parent names are joined by a conjunction that is not written. Conjunctive name extends parent and reduces number of substituents.

Nomenclature other than Substitutive Type 97

However seniority of such side chain is ignored when more number of ‘junior’ but

identical side chains, each containing same principal function as the senior chain, are present (example 4.28c). A multiple bond may link up the cyclic and acyclic components. Compound (4.29a) is cited as an example. But if there is unsaturation in acyclic component conjunctive nomenclature is not applied due to difficulty in specifying the site of unsaturation. For similar reason when side chain contains ketone conjunctive method is not applied. For examples see section 4.10. {

//

Ce on,cu,on Cyclopentadiene(4.29a)

a

' -propanenitrile

Wilt

i

ay No oN

2,2 -Bipyridine (4.29b)

A ring assembly name denoting names of identical parent hydrides only once prefixed with appropriate multiplicative name (example 4.29b) can be regarded as conjunctive name.

4.6 ADDITIVE NOMENCLATURE When the compounds appear partially or fully saturated by addition with atoms to one parent unsaturated compound, this type of nomenclature can be applied. The ‘added’ atom(s) is/are cited as additive prefix (hydrogen) or suffix (other than hydrogen atoms). The parents are often the accepted common names. For examples see compounds (4.30a—4.30c).

_

eee

1,2,3,4-Tetrahydronaphthalene (Common name: Tetralin)

(4.30a)

| Decahydronaphthalene (Common name: Decalin)

(4.30b)

oe

Hydroquinone (Common name: Quinol)

(4.30c)

Though not formally unsaturated, carbon (C) or methylene (:CH2) adds to some other

elements to yield compounds that are commonly mentioned by additive systems. Carbon tetrafluoride (CF,), methylene dibromide (CH,Br2) or simply methylene bromide (since CH,Br or any trivalent carbon compound is unknown), etc. are a few examples. For some more additive names see section 3.2.2.

hee

CO,H Homophthalic acid (4.3 1a)

H

N+

UO

y

a

Pyridin-1-ium (4.31b)

Homotropylium cation (4.31c)

98 Nomenclature of Organic Compounds

Addition of —CH,- to the skeleton is indicated by ‘homo-’ additive prefix; and addition of H* is mentioned by a suffix —‘ium’. These are exemplified by citation (4.31a—4.3l1c). Several IUPAC nomenclature systems involve assembly (additive operation) of names of different parts or components. Where the component names do not lose any atom, the assembled name looks like additive one. A few of these are enlisted in Fig. 4.5.

Actual type of Name

iodide,

Ethyl etc.

dimethyl

Methylenedioxy

ether,

methyl

alcohol,

Assembly of acyclic, or cyclic chains Functional class name (earlier called Radicofunctional names)

Multiplicative name

diacetic acid

4.7 SUBTRACTIVE NAMES A compound formed by the loss of some atoms or parts produces a different one for which a subtractive name may be given. Denoting such loss with appropriate prefix (see Table 4.3) now modifies the name of the parent compound to yield a subtractive name for the new one. Table 4.3: Prefix Names Used in Subtractive Names

Loss of Atoms / parts Hydrogen Water Methylene (-CH>-)

Demethyl-

Oxygen

/ Nor-

Examples of subtractive names are shown for compounds (4.32, 4.33 and 4.34b):

CO,H fe

HOCHat 5

0"

..0H 1

4

OH Deoxyribose

(strictly speaking it is 2-Deoxyribose) (4.32)

HI3

HO

H

4 OH

CO,H 2,3-Anhydro-D-

gluconic acid (4.33)

Ho's

5

(a) R = CH; : Cholesterol

(b)R=H _ : 10-Norcholesterol (4.34)

As an exception, in terpenoids (examples: 4.35 and 4.36) removal of —CH,- from all the methyls is indicated by ‘nor-’ prefix.

Nomenclature other than Substitutive Type 99 There are, however, subtractive operations that are mostly used as suffixes (see Fig. 4.6)

in various types of IUPAC nomenclature. Examples: See elsewhere.

R

Roe

R

R

R R = Me: Pinane R=H : Norpinane (4.36)

R = Me: Bornane R=H =: Norbornane (4.35) Suffix Names

Indicative of the loss of

-yne

2

SE

aaa

|

Two H from two consecutive carbons Four H from two consecutive carbons One H from a carbon center of parent Two H from the same carbon

H_ (hydride) H* (proton)

—

Fig. 4.6

4.8 MULTIPLICATIVE NOMENCLATURE This type of names is applicable to compounds having several (two or more) parent structures, each with a particular principal characteristic group (and only one in number), connected to a symmetrical multivalent group (simple or composite; for examples see below). If required, only the parent structures are numbered. Their linking position to the group, and the position of any substituent in these parents need to be cited. Some useful symmetrical multivalent groups are noted below:

—O—

Ie

:Oxy-

SOU ANG-

—NH— : Imino-

—N oO

(and aromatic) hydrocarbons whose structures are given below.

CH,CH

ee aie HCH,CH,CH;

CH;CHCH(CH,CH;)CH,CH(CH;),

ie CH)CH; xiv) CH;CH)CH> H(CH)2CH (CHa)2CHCH;CH CH;CHCH(CH)CH;)CH,CH(CH3), xvi)

pace

XVii)

:

xii) (CH3)3C C(CH,)3 xiii) [(C Hg)gC]gCH xv) [(C H3) 9CH CH y4C

110 Nomenclature of organic Compounds

5

XXIV)

ae iow, a

CeO

XXVi)

XXVIil)

“Uy OX

See g

Roe oY ae 4

XXXVill

= OL

Exercise

po ;:

a

AN

111

oy Dien =

‘

ZS-

Ay

Solutions to some selected problems in question 2: 1* hint: iii) iv)

Numbering of the parent chain is decided by alphabetical preference of groups. Longest chain is to be selected as parent. Chain length, numbers of substituents are indecisive in determining the parent chain; select the parent on

ix)

The basis of locants of 1“ and all other substituents.

Xv) XXi)

Write expanded constitutional structure. Several like substituents are present; length of the chain is not decisive in parent selection. Refer to

XX)

Same as xxi).

section 3.2.2c. xxvii) | Equal chain length; number of substituents decides the root chain. Xxvili) |Chain with lower state of hydrogenation is to be selected as parent. XXiXx) Chain length is decisive in choosing the root chain. XXX) Bipheny] parent be used preferably. xxxli) | Lowest possible locants to all substituents; decision at the first point ee difference. XXXV)

Follow hints in xxi)

XXXviii)

Assign a ring assembly name (vide section 3.1.5)

xXxxix) xLii)

Follow hints in xxi) A spiro-compound and name as such (vide section 3.1.4)

xLy)

A bicyclo-compound.

2”4 hint: iii)

iv)

[1,1-Dimethylethyl] (a single sub.) is alphabetically preferred to ethyl. In new recommendation the name of the first substituent is 2-methylpropan-2-y] and is not preferred to ethyl. The numbering of the parent is hence changed! Two substituted substituents are composed of exactly same words; preference in respect of assigning locant to these is to be done on the basis of 1“ citation (viz. lower locant) of substituent

112 Nomenclature of organic Compounds (secondary) in the radicals; i.e., 2-methylbutyl is preferred to 3-methylbutyl. In new recommendations the name of these substituents: 2-methylbutan-1-yl and 3-methylbutan-1-yl, and order of preference is unchanged. Even then there are two alternatives; now selection of parent is to be made on the basis of citation.

ix) Xv)

XXVili) XXX)

XXXI1) xLii) xLyv)

Locants to substituents in order of citation. The phenyl group with substituent at lowest position is assigned locants by normal digits, and the other by primed numbers. 1,1,5-Triethyl-3,3-dimethyl is preferred to 3,3,5-triethyl-1,1-dimethyl. Lowest locant to first substituent. Choose numbering between two alternatives: 1,2-dimethyl-5-ethyl or 1,6-dimethyl-3-ethyl.

Answers to Selected Problems in Question 2: ill)

3,6-Dimethy]-4-[1,1-dimethylethyl]-5-ethyloctane. Or, 3,6-Dimethy]-4-ethyl-5-[2-methylpropan-2-ylJoctane*.

iv)

6-[2-Methylbutyl]-7-[3-methylbutyl]dodecane. Or,

6-[2-Methylbutan-1-yl]-7-[3-methylbutan- 1 -yl]dodecane’.

1X)

3,8-Diethyl-7-[2-ethyl-4-methylhexyl]-7-[3-ethyl- 1-methylhexyl]-5, 10dimethyItridecane. Or, 3,8-Diethyl-7-[2-ethyl-4-methylhexan- 1 -yl]-7-[4-ethylheptan-2-yl]- 5,10dimethyltridecane’. XV) 2,6-Dimethy]-4,4-bis-[2-methylpropyl]heptane. Or, XXIi) Or, XXVII) XXVIiil) Or, XX1X) OK) XXXII)

2,6-Dimethy]-4,4-bis-[2-methylpropan-1-yl]heptane’,

1,2,3-Tris-[1,1-dimethylpropyl]cyclopropane. 1,2,3-Tri-[2-methylbutan-2-yl]cyclopropane’*. 1-Methy]l-2-phenylcyclohexane. 1-Ethyl-4-[2-methylcyclohexyl]benzene. 1-Ethy]-4-[2-methylcyclohexan-1-yl]benzene’. [4-Methylphenyl]cycloheptane. 4’-Ethyl-2-methylbiphenyl. 3,3-Dimethy]-1,1,5-triethylcyclohexane. xxxviil) 1,17:2’,1”:2”,1’’-Quatercyclopropane. XXXIX) 1,2,3-Tris-[1-cyclopropylethyl]cyclopropane. xLii) 6-Ethyl-1-methy] spiro[3.3]heptane. 1,2-Dimethyl-5-ethylbicyclo[2.2.1]heptane. xLy) #

: These alternative names substituents.

actually conform to recent recommendations

regarding the naming of alkyl

Exercise 113 3. Give IUPAC names to the following compounds, which contain only those characteristic groups that are cited as prefixes:

a)

i) CH3CH(NO2)CHCICH3

(C.U. 95)

ii) CICHZCHICH(CH3)CH2CH2Br

(C.U. 99)

iii) CH3CHCICH(CH3)CH2CH3

(B.U. 92)

iv) CHg3CHCICHBrCHICH,

(B.U. 93)

v)

(B.U. 93)

vi) CoHsO0CH»CH,OC 2Hs

(B.U. 96)

(V.U. 01)

viii) Pr—O—CHMeCH,CH;

(V-U. 92)

(CH3)gCCH20CH

Vil) (CgHs)2CHNO> ix)

x) oe

(V.U. 99)

O

ay

(V.U. 98)

b)

ii) FE

So

ceceBr Cl

Br

CH (CH3)CH)CH3 iil) CH3CH,;CHBrCHC

HCH (CH>CHs3)»

CHCICH,CH;

CH,CH,CH,CH; iv) EtOCH,CHCCH,CH;0Me CH,CHyI

OEt

v)

aii ese

vi) nen

ia

I

vil). [ClhCHCH)})CHCHCICH)Br ix)

E

OMe

vil)

x)

[BrCICHCH)],CHCF F

NO,

Pog:

I

| Cl

xil) EtO

ser I

Cl

Cl

XIV) : Br

Br

114 Nomenclature of organic Compounds Xv)

O.N

griha

Xvi)

Oa

Cl

CT "C} e

XVii)

tee XVili)

Br.

Br

Cl Cl

Xix)

Cl

Xx)

Br

C

aes

Solution of some selected problems in Question 3: 1" hint:

a) il)

Numbering of the parent chain is to be taken care of.

iv)

Citation (alphabetical) determining factor in numbering the parent chain.

Vv)

Assigning locants to substituents (i.e., parent numbering) is crucial.

vi)

Parent be selected so as to accommodate maximum substituents.

Vili) x)

Length of the chains be examined carefully for parent selection. The compound is a cyclic ether; epoxy-a bivalent group (equivalent to two substituent at two locants to the parent in this case.

substituents)-must be

b) ili)

Two pair of three-carbon branches each having one substituent at same location are competing for inclusion in parent chain; compare citation: bromo- vs methyl- and ethyl- vs chloro-.

Vv) Vii)

Parent (five-C chain) is to be selected from three two-carbon branches containing one substituent each. Three two-carbon branches (each having two substituents) are attached to a C-center & two of these

xiv) XViil) XX) Xx1) Or,

would constitute the parent. Compare different locant combinations of substituents for numbering the parent. Chain length is decisive in parent selection. Chain length is decisive in selecting the parent. Compare: 1-[1-Methylpropoxy ]butane against 2-Butoxybutane. 1-[Butan-2-yloxy]butane versus 2-[Butan-2-yloxy]butane

XX1i)

Ctate of oxidation (less hydrogenated) will decide parent.

Exercise

11

2" hint: a) ii)

‘ 1“ substituent is at locant ‘1’ from either end. Numbering is thus decided at the location of 2"

iv) v) Vi) viii) x)

substituent. Alphabetical: chloro- vs iodo1“ substituent (here methoxy at C-1) to be taken at lowest location. The middle two-carbon chain is to be taken as parent. Four carbon-chain with isopropoxy at C-2 would be parent. The parent continues beyond the carbon which is linked to epoxy oxygen.

b) iii) Vv)

For locant allocation compare the citation: bromo- vs chloro-. Chain with methoxy substituent (at C-1) be included in parent; then compare ethoxy against

propoxy (at C-4).

;

Vil)

One dichloro branch must be included in parent but not both; compare locant combinations:

xiv)

1,1,4,5- against 1,1,5,5-. Decision is reached at the locant of second substituent.

XX) Xxi)

There are two cyclopentane rings; find out number of substituents present with each ring. Select parent so as to place substituent at lower locant

Answers to Selected Problems 3:

a) il) iv) Vv)

5-Bromo-1-chloro-2-iodo-3-methylpentane. 3-Bromo-2-chloro-4-iodopentane. 2,2-Dimethy]-1-methoxypropane

v1)

1,2-Diethoxyethane.

vill) | 2-Isopropoxybutane. x) 1,4-Epoxy-2-methylpentane. Or, 2,4-Dimethyltetrahydrofuran (Hantzsch-Widman name)

b)

ill) 3-Bromo-6-chloro-5-[1-ethylpropyl]-4-[1-methylpropyl]octane Vv) 4-Ethoxy-1-methoxy-3-[1-propoxyethyl]pentane. Vil) 5-Bromo-3-[2,2-dichloroethyl]-1,1,4-trichloropentane. xiv) 3,4-Dibromo-1,1-dichlorocyclohexane. xviii) 1-[2,2-Dibromocyclopropyl]butane. 1-Bromo-2-[2-cyclopentylcyclopropyl]cyclopentane. XX) xxi) 1-[1-Methylpropoxy]butane. : Or, \-[Butan-2-yloxy]butane. xxii) | 1-Pentyloxycyclopentane. Or, [Pentan-1-yloxy]cyclopentane.

116 Nomenclature of organic Compounds

4. Write IUPAC names for the following compounds containing one or more unsaturation a

ix) CH3CH=CHC(CH3)—=CHCH(CH3)CH2CH3 (B.U. 98)

;(CH3)2CHCH2C=CH

(C.U. 89)

ii) (CH3)3CCHsC=CH

(V.U. 87)

iii) CH3CH(CH3)C=CCH3

~—(V.U. 93)

x) HoC=CHCH2C=CH

iv) HC=C—CH(CHs3)2

(B.U. 94)

xi) HpC=CHCH,CH,C=CH

(V.U. 88)

v) CH3CHsCH(CH3)C=CCHs (C.U. 90)

xii) CHs3CH=CHCH(CH3)C=CH_

(V.U. 95)

vi) (CH3)3CCH=CHC(CH3)3_

xiii) CHsC=C—CH=CHCH3

(C.U. 95)

(V.U. 93)

vii) CH3CH2CH(CH3)C=CH_ = (B.U. 97)

viii) CHsCH=CHCH,C=CH

(C.U. 99) (B.U. 96)

xiv) CH3CH2CH(CH=CH2)CH2CH2CH3

(C.U. 89)

= (B.U. 95)

b)

oe e

ii)

il)

Bis 2)

vi) ((CH3)CH],CHCH=CH)

vii) (CH;);CC=CCH(CH3))

ix) [CH3CH,CH},C=C[CHCH,CHs]p

x)

CH,

UGH aalatie GH

ales

CH,

CH;

xi) xiv)

XVi)

a7

=< lyqowgetoporeners =,

ants

fen ——

| Rear

Exercise

XXi)

[H»>C=CH],C

;

xxiii)

XxXil)

11

[H,C=CH]3;CC=CCH;

xxiv)

[H2C—=CH]oC [C=CH], Ph Me

Ph

=< xxxi)

y,

XXx2H

CO>H

CH»[CH2]4C O2H

[CH2],CH=CHC 02H

[CH2](C 02H

ii)

CH,

i aS

peri

NC

;

CH[CH)]xCN

Exercise 133

iv)

IS:

v)

ait

Svar tty

HeNOG ‘CHO

OH

OH

OH

ual HO2C

SH COoH

es Br

viiib)

COBr

a

COBr

OH

|

HOoC

O

©)

CO2Me

Oe Br

iar

CO2H

MeOoC

|

COoH

134 Nomenclature of organic Compounds Solution to Selected Problems 10: Hints:

i) il) iii) iv)

Vv)

viia) Viiib) ixa) ixb)

Numbering direction would be different on the two isomeric compounds; after principal function multiple bond be given precedence over other substituents. Parent selection is crucial; two -CO,H cannot -be included. Hence length of the chain is decisive in the first whereas inclusion of double bond decides in the later two. In the second chain length is decisive whereas in the first state of oxidation (lower state of hydrogenation) is decisive in parent selection. —CHO is principal function in the first and hence both are to be included in parent but in the second this is preceded by amide function and hence —CHO is left out and longer chain inclusive of amide C constitutes the parent. Both the —OH are given lower locants in the first, in the 2™ and 3 numbering route is directed along C=C after starting from senior-most function. The first compound needs naming using heterocyclic parent; the second can be given a name derived from heterocyclic parent or an acylic parent having epoxy substituent. —COOH is principal characteristic group and parent is to be chosen on that basis. Both can be given names following heterocyclic parent (namely benzofuran); however the a" compound maybe named as an anhydride. Both the compounds are conveniently named as bridged compounds; however the 1“ one is easily named as an anhydride.

Answers to Problems 10:

i)

2-Bromo-2-methylcyclopent-3-en-1-one 5-Bromo-5-methylcyclopent-2-en-1-one 4-[5-Carboxypentyl]cyclohexane-1-carboxylic acid. 5-[4-Carboxycyclohexyl]pent-2-en-1-oic acid. 4-[6-Carboxyheptyl]cyclohex-2-ene-1-carboxylic acid. 3-[4-Cyanobutyl]cyclopentanecarbonitrile 5-[3-Cyanocyclopentyl]hexanenitrile 2,2-Bis[2-hydroxyethyl]propane-1 ,3-dial 2-Formyl-4-hydroxy-2-[2-hydroxyethyl]butanamide

ii) iii) iv)

Cyclohexa-4-ene-1,3-diol

Vv)

vila)

vilib) iXa)

ixb)

5-Sulfanylcyclohex-3-en-1-ol 5-Hydroxycyclohex-2-en-1-one 3,5-Dipropyloxane Or, 2,4-Dipropyl-1,5-epoxypentane 2,6-Dipropyloxane Or, 4,8-Epoxyundecane 3-Bromo-3-[3-bromoformylphenyl]propanoic acid 3-[1-Bromo-2-bromofromylethyl]benzoic acid Benzo[b]furan-2,3-dione Isobenzofuran- |!,3-dione

Or, Benzene-1!,2-dicarboxylic anhydride 3-Oxabicyclo[3.2.2Jnonane-2,4-dione 2-Oxabicyclo[3.2.2]nonane-3,4-dione

{Phthalic anhydride (common name)} Or, Cyclohexane-1,4-dicarboxylic anhydride

Exercise 135

11. Choose

the correct name(s)

from

several given names.

Only one name

in a

particular type of nomenclature would be correct. However, more than one name (each in different type) can be found correct fer a given compound.

i) 4-Formylbutan-2-one Pentan-1,4-dione

4-Oxopentanal 1-Oxopentan-4-one

4-Oxobutanenitrile

3-Formylpropanenitrile 3-Cyanopropanal ili)

4-Carboxyhexane-1-sulfonic acid 2-Ethy1-5-sulfopentanoic acid 6-Sulfohexane-3-carboxylic acid Hexane-1-sulfonic acid-4-carboxylic acid 3-Oxobutane-1,2-diol 2-Oxobutane-3,4-diol

CH; CO CHOH CH,0OH

1 ,2-Dihydroxybutan-3-one 3,4-Dihydroxybutan-2-one

(2-Aminoethy])(propyl)aminomethanol b) N-[{Hydroxymethyl]-N-propylethane-1,2-diamine N-[{2-Aminoethyl]]-N-hydroxymethylpropan-|-amine 2-[2-Aminoethyl]-2-azapentan-1-ol

Clg oe

C=O] it) GD) [-CN is senior to -CHO, and formyl prefix rather than oxo for aldehyde] iii) :(b) [-COOH is senior to -SO3H] iv) :(d) [-seniority of >C=O over —OH is important consideration] v) :(a) and (d) [again seniority of -OH to amine is decisive] vi) :(a) and (f) [the last name is conjunctive] vii) :(b), (c), (d) [the 1* uses -anilide suffix; the 2" is a substitutive name; the 3™ uses a functional parent] viii):(b) and (d) [the name (d) uses the recent suggestion by IUPAC for naming an alkyl

1x) :(b)

group; the name (b) is used by CAS] [the critical feature is preference of multiple bond after the principal function]

x) :(a) and (d) [the name (d) is based on heterocyclic parent). xi) :(d), (e), (f) [(d) is a functional modifier name ; (e) is a substitutive name using continuous C-chain as parent; (f) is correct replacement name.

Exercise 137

12. Try to draw structures from the names given below. In some cases the names are incomplete and hence structures cannot be drawn. Give reason why those names are incomplete. Others are incorrect names though structures of these can be drawn. Give correct names for them. 1-Methylpentane 2-Ethylhexane 4-[1-Methylpropyl] heptane. Or, 4-[Butan-2-yl]heptane 5,6-Dimethyl-3-ethyloctane 4-Ethyl-5-[1,1-dimethylethyl]octane. Or, 4-Ethyl-5-[2-methylpropanan-2-yl]octane 5-Bromo-1-ethyl-2-methylcyclohexene 4-Chloro-2-ethyl-1-methylcyclopentene 2-Phenethylbenzene 1-Phenylpentane re nd aed Faas al lA Sedge Methylhexane Dimethylcyclohexane 2-Pentenone 3-Methyloctyne 1-Hydroxy-2-ethylhexan-4-one 3-methylcyclohex-4-en- 1-one 3-Ethylhexanamine Cyclohexanoic acid 4-Etheny]-2-methylheptan- 1-ol 4-[Prop-1-en-1-yl]-3,4-dimethyloctan-2-one

3,5-dihydroxy-2-ethynylpentanamide 1-Ethoxyethan-1-one 1-Bromopropan- 1-one 1-(N-Methylamino)butan- 1-one

1-Hydroxypentan-1,4-dione 1,4-Epoxy-1,4-dione

1-Oxobutan-1-ol 1-Acetoxypropan-1-one Bis(1-oxoethyl)ether Ethanoyl amine Diethanoy] amine N-Ethyl-N-methylpropanamine 3-Aza-6-thia-8-oxanonane 1,3,5-Trioxahexane

Cyclohexane-1-ethanoic acid-2-propanoic acid Cyclopentanepentane-1,2-diol Isopropanol tert-Butanol Isopentene

138 Nomenclature of organic Compounds Answers to Problems 12: | — 2. Longer chains are not recognized as parent. The names would be 1. Hexane 2. 3-Methylheptane 3. Parent is not selected properly; chain length being equal parent is to be decided here on the basis of higher number of substituents. The name would be 3-Methyl-4-[propan-1-yl]heptane

(43.1)

(13.2)

(13.3)

4 —7. Parent chains are wrongly numbered (i.e., locants not as per rules). 4. The numbering is to be decided at the 2" substituent (not alphabetically), 6-Ethyl-3,4-dimethyloctane

5. The locant here is to be allocated on the basis of alphabetic preference, 4-[1,1-Dimethylethyl]-5-ethyloctane 6. The numbering is decided at 3“ substituent, 4-Bromo-2-ethyl-1-methylcyclohexene

7. Positions of substituents are same in either direction the numbering is to decided by alphabetic preference, 4-Chloro-1-ethyl-2-methylcyclopentene 8. Length of chain is ignored when several identical substituents are present, and number of total substituents in a chain is given precedence in choosing the parent. 1,2-Diphenylethane

(13.4)

(13.5)

(13.6)

(13.8)

(13.9)

C.gH (13.7) 9. Same as | and 2. [Pentan-1-yl] benzene.

Or, Pentylbenzene

10—13.Locations of one or more substituents (either prefix or suffix) are not mentioned. So structures cannot be drawn. 14. Parent is wrongly selected; 4-Hydroxymethytheptan-3-one

a

Exercise 139 ee SS ee ee a a. 15. Numbering is done improperly; multiple bond comes next to principal function in terms of seniority, 5-Methylcyclohex-3-en-1-one 16. Location of amine group is not provided. So structure cannot be drawn. 17. —oic acid suffix indicates a carboxylic acid excluding the C of the group; this monovalent C cannot be part of a ring parent (as shown by str. 13.17a). The name would be cyclohexane carboxylic acid of course if the presumed structure were 13.17. A O O COOH i

ee

(13.14)

Me

(13.15)

On )

tei

(13.17 a)

(13.17)

18—20.In these three names parent chains are not properly selected. After principal function parent would proceed along multiple bond irrespective of length of the chain. 18. 2-Methyl-4-[propan-1-yl]hex-5-en-1-ol 19. 4-[Butan-1-yl]-3,4-dimethylhept-5-en-2-one 20. 2-[1,3-Dihydroxypropan-1-yl]but-3-yn-1-amide

Ne ee eee nooo (13.18)

(13.19)

(13.20)

21—29.The functionalities are not correctly diagnosed. Though structures can be drawn, the

names are unacceptable’. 21. 22. 23. 24. 25. 26. 27. 28.

It is an ester. Ethyl ethanoate It is an acid bromide. Propanoyl bromide It is an N-substituted amide. N-Methylbutanamide It contains one ketone and one acid group. 4-Oxopentanoic acid It is an anhydride. Butan-1,4-dioic anhydride. It contains one acid group. Butanoic acid. It is actually a mixed anhydride. Ethanoic propanoic anhydride. An anhydride is wrongly named as ether by functional class name. Ethanoic anhydride. 29. An amide functionality is wrongly split. Ethanamide

The structures of compounds, 21—29, are given in the next page. *In seven (21-28) of the above examples a characteristic group is wrongly diagnosed as being summation of two or more characteristic groups. So one must be careful to identify the functional groups correctly (vide section 2.4). However Replacement System of Nomenclature of polymeric

compounds is in use (the polyesters, polyamides, polycarbonates, etc.) where the characteristic groups seem to lose ‘identity’/ familiarity. For Examples see Appendix - VI.

40 Nomenclature of organic Compounds

aca

nd een

(13.21)

(13.22) ZO

O

O x

(13.28)

(13.27)

o

(13.26 . ) O

O

O

O

(13.23)

(13.25)2

R (13.24)

NHCH3

O

(13.29)

30. It is a correct name. An imide functional group is so named.

31. The location (may be 1 or 2 in this case) of principal function is not mentioned. 32. The parent is numbered wrongly. 7-Aza-2-oxa-4-thianonane

33. A terminal hetrero-atom is not named as “a” prefix in replacement nomenclature.

2,4-Dioxapentan-1-ol. 34. If side chains (with principal function each) are of unequal length only the longer is shown by conjunctive name, the shorter one(s) is(are) written as prefix(es). 2- Poorpomaeh acid.

(13.530)

(13.32)

(13.33) (13.36)

COOH (13.34)

(CH3)3COH (13.35)

(13.37)

35. Usually conjunctive names are not used when there is more than one principal function. Also numerical locant is not used for acyclic part in conjunctive naming. 5-Cyclopentylpentan-1 ,2-diol. 36—38.The names are not recommended for lack of parent as isopentane and tert-butane. 36. Propan-2-ol Or, Isopropyl alcohol 37.2-Methylpropan-2-ol Or, tert-Butyl alcohol. 38. Structure cannot be drawn

Exercise

141

13. Give a relatively simple name to each of the following compounds. Be careful to select the type of name.

CO.H v)

vi)

HO,C

H vii)

N

CO2H

H

‘aSS

viii)

N

pp ecretioan

BO: aw, ____ abe < N

N

S

xi)

x

OH

*) O40CHb O CH»

[n

NCH, 0 CH;CO.H buy 0 CH,CO;H

Answers to Problems 13:

i)

Bis[triethylmethyl] amine (substitutive name).

ii) ili) iv) v) vi) vii) viii) Or,

3,3,5,5-Tetra[carboxymethyl]-4-azaheptane-1,7-dioic acid (replacement name). 3,5-Diethyl-4-azaheptane-1,7-dioic acid (replacement name). 3-[{(1-Ethylpropan-1-yl)amino] pentane-1,5-dioic acid (substitutive name). 2,4,6-Triethylpiperidine (Hantzsch-Widman name). 4-Ethylpiperidine-2,6-diacetic acid (conjunctive name). 3-[Ethoxymethylsulfanyl] pyrrole (substitutive name using heterocyclic parent). B-Oxa-6 -thiapyrrole-3-pentanoic acid (conjunctive name). 5-[Pyrrol-3-yl]-3-oxa-5-thiapentanoic acid (replacement name).

ix) x) xi) xii)

Thieno[3,2-b]furan (fusion name) 5H-[1,4]Thiaoxano[6,5-b]pyrrole (fusion name) 1-Azabicyclo[2.2.1]heptane-3-ethanol (conjunctive name). 3,3’,3”-Trioxa-4,4’,4’-nitrilotributanoic acid (multiplicative name).

142 Nomenclature of organic Compounds

14. Draw structures of the compounds from the names given bellow. 1)

4-[2-Chloroethyl)hexane- 1 ,4-diol

2) 3)

2-Bromo-4-methoxy but-2-en-1-oic acid a-Chloropheny]! ethanoate

4)

[6-(2-Bromoethyl)cyclohex-2-en-1-yl]methanol

5) 6) 7)

N-[2-Methylpropyl]-4,5-dihydroxydec-2-en-1-amide 5-[3,4-Methylenedioxyphenyl]penta-2,4-dienoic acid 2-Acetoxybenzoic acid

8)

N-[4-Ethoxyphenyl]ethanamide (Phenacetin)

9)

2,6-Dimethylhepta-2,5-dien-4-one

10) 11)

N,2-Dimethyl-4-nitrobenzamide 1,4-Dihydronaphthalene-1,4-dione

12) 13) 14) 15) 16)

4-Ethenyl-2-methylhept-6-en-3-ol 4-[N,N’-Dimethyl- N’-phenyldiazenyl]benzenesulfonic acid 2-Methylidenecyclohexanone 4-Propanylidenecycloheptanecarboxylic acid. 2H-Pyran-6-carboxylic acid

17)

18) 19)

2,3’-Bipyridine

Indole-3-acetic acid Indane-2-butanoic acid

20) 21) 22) 23)

Naphthalene-1,6-dipropanoyl chloride 2-Carboxymethyl- ,B-dimethylcyclohexanepentanoic acid N,N’-Diethylbenzene-1,3-dipropanamine o,a’-Dimethylcyclopentane-1,2-diethanol

24) 25)

2,4,7-Trioxaoctane 5-Aza-7-oxa-2-thiadecane

26)

4-Ethyl -1-oxa-4-azacyclohexane (i.e., N-ethylmorpholine)

27) 28) 29) 30)

6-[2,4-Dioxapentan-1-yl]-6-aza-3,9,11-trioxadodecanoic acid Benz{a]Janthracene Benz{[c]pyridine (i.e., Isoquinoline) Naphtho[2,1-f]quinoline

31) 32) 33) 34)

Styrene oxide Stilbene dibromide Homophthalic acid Homotropylium cation

35)

DichloroC?H 1 methane

37) 38) 39)

Cyclopent-2,4-dien-1-yl cation (Or, Cyclopent-2,4-dien-1-ylium) Butan-2-ide (Or, Butan-2-yl anion) Diphenylmethylene (Or, Diphenylcarbene)

40)

4-Ammoniobenzene sulfonate

41)

Pyridinium-1-carboxylate

36)

(2,2,0-"H)Ethanol

Exercise 143

42) 43)

2-Phenylethyl acetoacetate 1-Proto-1-pyridinium sulfonate

Answers to Problems 14:

For solution to these problems section 3.9 may be consulted. Here the parent plus the suffix part (which is required to be drawn first) in shown in light colour.

CHeOH

to

Br

Me™

17)

€X_N }< Nor )

1) ( JT x

~S

Sub t.gxB ae

con a,

i

p)

26)

Pye

Ano

oe

eee

2 econ

O

eA eee NHEt

22

N—CoHs

O iil 9 a

0. cou sa y SEE

33)

Ar

ecg G4 bea

7i

Name be better written as (alphabetical):

5-Ethyl-2-[2-methylpropyl]phenol Ph

ix]

AS ;

Nf

Cl

x]

5

3

el

1

CHO

xii] xi]

i

xii]

4

ae

—oge OH

The correct name would be: trans-Pent-4-en-2-ol

pers

x

rap ery?

floral cantontstied‘adoma sit] ¢-deaardqfigqagiom-f}-S-lydd-2 iv)

ey

lien

\-nic

acid

iy, T-Hnerwa “OE 4

i

aes) 2. n [x a

aad

Or, HA: 1viheilislietanaesianid fe.

4 mnogmengir! 3-mnethep ft ee

iam

ae a

La =A a ix i

8

Appendix I. Parent and/or numbering is /are changed or not when unsaturation is present Sometimes parent including its numbering (i — b, ii — b and iii - b) remain the same, sometimes (i — c, ii —c and iii - c) only numbering is changed, and in others (i — d, ii — d and iii — d) parent is changed. Unsubstituted alkene

fetes eiwasoii

4- Ss as-2-ene (ii -a)

3-Ethylhexane

(iii -a)

Parent and its numbering unchanged

H

—_‘Parent chain unchanged but numbering changed

Parent chain changed

COOH

ea

cetop -2-en-1-al (ii -b)

ee

ee

(iii -b)

-amine

nips oe

4- Se -5-en-2-one (ii -C)

4-Ethylhexan-2-amine

(iii -c)

ed

3-sit,iy -en-2-one (ii -d sone

AN -amine

(iii -d)

See sections 2.3 and 2.3.1 for general guidelines for parent identification and selection.

II. Exceptions where non-continuous C-chain is selected as Parent The following exceptions may be noted: (a) Heterogeneous hydrides consisting of carbon atoms and several heteroatoms, alike or different, and terminating with carbons can have parent names with continuous carbon chain. This is replacement (skeleton) nomenclature (see section 4.1). (b) Monocyclic compounds with less than 10 ring members and having one or more heteroatom(s) can have a parent name with noncontinuous C-chain in extended Hantzsch- Widman nomenclature system. (c) Normally a parent is an hydride of unbranched chain of same element e.g., phosphane, silane, etc. Thus pentasilane is H,Si-SiH2-SiH2-SiH2-SiH3 However, there are a few examples of parent names containing different elements e.g., disiloxane iS H3Si-O-SiH;

150 Nomenclature of Organic Compounds

IL. Some Cases where Olefinic carbons of same C=C do not get consecutive locants (a) For compounds with fixed numbering the two olefinic carbons may not receive consecutive numbers. In such cases locants of both carbons are to be cited — the higher locant in parenthesis, e.g., 13 1

1 yy

Bicyclo[5.4.2]tridec-1(11)-ene

(IIa) (b) In conjunctive nomenclature if the cyclic and acyclic components are connected by a double bond the position of —‘ene’ is indicated by locants of the two chains; in that case there is no question of c=c to get two consecutive numbers and hence both numbers are to be shown, e.g.,

Wier

«,

Cyclohexane-A" °-propanoic acid

(IIIb) IV. Multiplying Affix(es) for Repeated Substituted Substituents Repeated occurrence affixes:

of similarly substituted substituents is denoted by the following multiplying

Number

Affix term

ae b. ce

Bis Tris Tetrakis*

d.

Pentakis*;

Etc.*

*kis is added to the basic numeral term given in Table 2.8 . Examples to show use of such affixes are cited bellow. Cl

Br

Cl

Br

B i

Br

CO>H

OH

HO 2C a

Cl

Cl 4,5-Bis[1,1-dimethyl-

ethyl]octane

(IVa)

Cl

2,5,6-Tris[ 1, 1-dichloroethyl]-

octan-1,8-dioic acid

(IVb)

Br

"

Br

" Br 2,3,4,5-Tetrakis[ 1,2-dibromo-

ethyl]octan-1-ol

(IVc)

Appendix 151

V. Restriction of Applying Replacement Names Replacement names such as these (examples Va — Vd) are not recommended.

1

g

2 y CHa—-C—O-Ch

CHs—-C—O-C—CH;

3-Oxo-2-oxabutane

CHs—CHp—C-O-NHCH3 3-Oxo-2-azapentane

2,4-Dioxo-3-oxapentane

(Va)

(Vb)

ors

= CHaCH2NCH2CH2CHg 3-Methyl-3-azahexane

(Vc)

(Vd)

VI. Polymeric Compounds with Replacement Names Examples of replacement names characteristic group names.

for polymers

ee O ON

O

are found though this results in the loss of their

VAY O YC tard Es

O

O

O

2,6,10,18,22,26-Hexaoxa-14-thiaheptacosane-3, 7,11,17,21,25-hexone

(VIa) [(CH3CH,NHCOCH,CH,NHCOCH>CH)],0 3,7,15,19-Tetraaza-11-oxa-4, 8,16,20-tetraone

(VIb) A characteristic group gets an uncharacteristic name! In above two compounds ester (Va) and amide (Vb) groups are given suffix name ‘“—one’ which is actually that of a ketone. In the following example (Vc) suffix “-ene’ is used for azo group.

a 6,7-Diazadodeca-?,6, | 1-triene

(VIc) The ‘identity’ crisis of a characteristic group is also felt in Hantzsch-Widman naming of lactones, imides and anhydrides (vide section 4.3.1).

152 Nomenclature of Organic Compounds

VII. Azacrowns and Cryptands Azacrowns are macrocyclic polyamines; the O of the ring being replaced by N. IUPAC (examples VIIc and VIId) uses replacement prefix names of N as aza.

naming

Naming of three complex crown ethers are exemplified with compounds (VIIa), (VIIb) and (VIIc).

These are named as tricycic compounds (see section 3.1.4: Bridged Cyclic Systems with more rings; pages 37, 38)

an

26 3 ‘ 22

8

9

21

2,5,8,15,18,21-Hexaoxatricyclo[20.4.0.0%!4]-

2,5,8,15,18,21-Hexaoxatricyclo-[20.4.0.07!4]-hexacosa-

hexacosane

1(22),9,11,13,23,25-hexaene

Short name: Dicyclohexano[18]crown-6 (VIIa)

O

Short name: Dibenzo[18]crown-6 (VIIb)

O —_

VA

\N

N \

\ HN

NH

HN

y

—=

Q

/ NH

pe

3,6,14,17-Tetraoxa-23,24-diaza-tricyclo[17.3.1.1°!7)-

eg 1,4,7,10-Tetraaza-cyclododecane

tetracosa-1(23),8,10,12(24),19,21-hexaene

(VIIc)

(VIId)

Poly macrocyclic bridged compounds having heteroatoms in more than two bridges are called cryptands. These are three-dimensional variations of crown ethers. Two such compounds are named as illustrative examples (VIe and VIIf).

a

Neo

(ios

Oma

See) O

O

NES 4,7,13,16,21,24-Hexaoxa-1,10-diaza-bicyclo[8.8.8]hexacosane (VHe)

N

(Cea)

N

O

Na 4,7,13,16-Tetraoxa-21,24-dithia-1,10-diaza-

bicyclo[8.8.8 ]hexacosane (VIIf)

Appendix 153

Suggested Further Reading: 1.

A guide to IUPAC Nomenclature of Organic Compounds; R. Panico, W. H. Powell, and Jean-Claude Richer, Blackwell Science, 1993

2.

Nomenclature of Organic Chemistry; Rigaudy, J. and Klesney, S.P. Pergamon, 1979

3.

Nomenclature of Organic Compounds: Principles and Practice; 2" Edition, Edited by Robert B. Fox And Warren. H. Powell, Oxford University Press, May 2001

4.

Nomenclature of Organic Chemistry; Sections A, B, C, D, E, F, and H, Pergamon press, Oxford, 1979.

5.

A Guide to IUPAC Nomenclature of Organic Compounds (Recommendations 1993); 1993, Blackwell Scientific publications.

6.

Nomenclature of Organic Compounds, Oxford University Press, NY, 2001

2"! edition; R. B. Fox and W. H. Powell,

7.

IUPAC Nomenclature of Organic Compounds;

www.acdlabs.com/iupac/nomenclature/

-

oe

ae

BA 1617 -Fetyecn TRA eeeariepeiogy? Lg. area

11)

80,

PI,

299 eee

=| cmgomh Jicwies!

pene hemes jcc

to mae Gt re

of crowe Chet

Ted ech

INDEX “a”’-prefix, 88,92 Acetal, 44 -cyclic, 44 Acid

-anhydride, 57, 58 -carbamic, 63 -cabonic, 62 -carboxylic, 52 -trivial names, 54, 55 -salts, 57 -hydroxamic, 62 -sulfonic, 56 -derivatives, 57 Acid halides, 52, 90 Acid salts, 59 Acylals, 59 Adamantane, 38 Additive Nomenclature, see Names, additive Affix -multiplying, 30, 150 Alcohols, 51 -salts, 51 -trivial names, 52 Aldehydes, 52 Amides, 52 -secondary, 60, 61

-tertiary, 60, 61

-poly -symmetrically substituted, 61 -asymmetrically substituted, 61 Amines, 48, 87

-asymmetrically substituted, 50 -cyclic, 19, 50 -di, 50 -poly, 50 -secondary, 49 -symmetrically substituted, 50 -tertiary, 49 -trivial names, 50 Amidines, 62 Anhydride, 18, 56, 57, 58

-cyclic, 94 -semisystematic names, 58 -trivial names, 58 Anilides, 61

Anions

-naming of, 70 -monovalent, 31 Arenes, 39 Atom

-spiro, 38 -super, 39 Azane, 48, 67 Azacrowns, 45, 152 Azides, 40, 90 Azo-compounds, 44, 67, 69 Azoxy compound, 68

Bridged compounds, 37 -with more rings, 37 Bonds, -double, 15 -multiple, 13, 14, 16 Carbamides, 63

Carbodi-imide, 67, 68 Carbonic acid, 62 -derivatives, 62 Carboxylic acid, 52 Cartoons, 1, 144 CAS, 30, 31, 87 Cations, 31 -naming, 71 Chain, 16 -acyclic, 10,84, 103 -continuous, 10; noncontinuous, 149 -cyclic, 10, 84, 103

-principal / parent, 19 Characteristic group, 16, 19, 31, 32 see also groups, characteristic -identification, 16 -monoatomic, 16, 17 -diatomic, 17 -triatomic, 17

-polyatomic, 16 -principal, 5, 6 Compounds -azo, 44, 67, 69

-azoxy, 68 -bridged, 37 -monocyclic, 149 -organometallic, 65 -polymeric, 151

156 Nomenclature of Organic Compounds Compounds (continued from previous page) -specific type, 65 -spiro, 38

-symmetrically branched, 101

substituted, 101 -isotopically modified, 66 Conjunctive Nomenclature, see Names, conjunctive Crown ethers, 44, 45 Cryptands, 45, 152 Cubane, 38

Cyclophanes, 39 Diazane, 68 Diazanyl, 67, 68 Diazene, 67, 68 Diazenyl, 67 A-prefix, 97, 150 Esters, 57 -cyclic, 64 -mono, of polybasic acids, 57,59 -of halogen acids, 60 -of nitric acid, 60 -of nitrous acid, 60 -of phosphorous acids, 60 -sulfur acids, 57 Ethers, 44 -crown, 44

-cyclic, 44 -prefix names, 18 Fullerene, 3 Functionality, 23, 80 Freons, 43 Functional class Nomenclature, see Names, functional class

Functional -group bivalent, 61 -modifier, 90 -replacement, 92 -parent, 82 Fusion Nomenclature, see Names, fusion

Glycerides, 59 Groups -acyl, 28 -alkanyl, 24, 25 -alkenyl, 24, 25 -alkyl, 23, 26

-alkylidene, 28 -alkylidyne, 28 -aralkyl, 27 -aryl, 25 -functional, 5, 17 -principal, 6, 13, 14, 16, 20, 82

-symmetrical, multivalent, 99 Half-acid, 59 Half-ester, 59 Halides, 44, 90 Hantzsch-Widman system, 18 Hantzsch-Widman Nomenclature, see Names, Hantzsch-Widman Heteroatom, 5, 19, 20, 37, 88, 89, 90, 92, 103 Heterocycles, 19, 58, 92 Homo-prefix, 97

Hydrocarbons, -aromatic, 33 -branched, 33 -saturated, 30, 33 -unbranched, 10 -unsaturated, 33 -fully, 10 Hydrazides, -N-substituted, 60 Hydrides, -heterogeneous, 149 -homogeneous polynuclear, 67 Hydrogen -indicated, 36 -primary, 26 -secondary, 26 -tertiary, 26 Hydroxamic acid, 62 -derivatives, 62 Hydroxylamine, 67, 68 Imides, 62, 94 -cyclic, 62, 94 Imines, 48 Infix, 84 Ion, 1 -zwitter, 73 MOE, 2 IUPAC, 2, 26, 46, 54, 55, 98 Isotopically modified compound, 66 Ketenes, 63, 64

Index 157 Ketal, 44 -cyclic, 44 Ketones, 63 -trivial names, 64, 65 Lactams, 18, 64

-heterocyclic name, 94 Lactim, 18, 64 Lactones, 18, 64 -heterocyclic name, 94 Ligands, -anionic, 65, 66

Locant, 15, See also -lowest, -of C=C

22 numbering 36 bond, 36, 97, 150

-a, B, etc., 96 M"-prefix, 67, 88 Maximum length -for parent selection, 14

Multiplicative Names See Names, multiplicative

Multiplying affix, 150 Multivalent group -symmetrical, 99 Names, (also see nomenclature) -additive, 2, 3, 4, 97 -conjunctive, 2, 3, 82, 95, 103, 150 -functional class, 2, 3, 5, 43, 90, 103 -fusion, 2, 94 -generic, 45, 48 -Hantzsch-Widman, 2, 3, 92, 149 -multiplicative, 2, 3, 99, 103 -prefix, 5, 6, 17, 31, 98

-principles of, 5 -replacement, 2, 3, 4, 87, 103, 151

-ring assembly, 100 -semisystematic, 1, 27, 56, 92, 95 -substitutive, 2, 3, 33 -subtractive, 2, 3, 98 -suffix, 17, 31, 33, 96 (see also suffix) -trivial/common, 1, 6, 27, 43, 45, 92, 100 -types of, 2 Nitriles, 52 Nomenclature, (see also Names)

-of heterogeneous hydride, 149 -operation, 2, 6

-phane, 4 -systematic approach to, 73 Nor, prefix, 98

Numbering, 47 -alphabetical, 20, 36, 42 -fixed, 19, 36 -heteroatom, 19 -indicated H, 19, 36 -pattern, 36, 41 Numeral terms, 6, 30

Order of precedence, 21, 37 Organometallic compound, 65 Oxidane, 1, 67, 144 Parent, 5, 149 -choice of, 40 -functional, 10, 82, 103 -hydrides, 24, 30 -identification, 10 -mononuclear, 67 -names, 11, 12, 30 -non-continuous C-chain, 149 -non-functional, 10 -selection, 13, 45 -skeleton, 80, 84 -structure, 11, 12 Phane Nomenclature, 4 Phenols, 51

Polyethers, 45 Polymeric compounds -replacement names, 151 Polysulfides, 45 Polynuclear hydrides, -homogeneous, 67

-heteronuclear, 67 Prefix, 5, 6, 7, 84, 89, 97, 98 -‘a’”’, 88 -iso, 26 -neo, 26 -sec, 26

-multiplicative, 6, 22 -for substitutive names, 33 -A, 97, 150 ah O18 Principal Characteristic groups

-priority order, 31 Prisnmane, 38 Priority order, 31

158 Nomenclature of Organic Compounds Radicals, 1, 3, 26, 90

-acyl, 55 -multivalent, 27 -naming, 72 -prefix, 31 -suffix, 31

Replacement Nomenclature, see Names, replacement Ring -assemblies, 38

-polycyclic, 94 Rules, -additional, 34 Salts -diazonium, 71 -neutral, 57 -of acids, 57 -of alcohols, 51 -of halfacid-half esters, 59 -of sulfur acids, 57

-partially esterified, 60 Semicarbazide, 67, 68 Sketch, diagrammatic, 7, 8, 9, 10

Spiro-atom, 38 Spirocompound, 38

-cyclic, 37 -primary, 7 -secondary, 7 -subsidiary, 29 -substituted, 27 Substitutive -nomenclature, 2, 33 Subtractive modification, 5, 6 Sultams, 18 Sultones, 18

Super atom, 39 Symmetrically substituted compound, 101 Symmetrically branched compound, 101 Term

-basic numeral, 30 -functional class, 90 Tetrazane, 67, 68 Thioalcohols, 51 Thioethers, 43, 90 Thiols, 51 Thiophenols, 51 Thiourea, 67 Triazane, 68 Trivial names (see also Names, trivial)

Stems

-of acids, 54, 55

-for rings with heteroatom, 93 Suffix, 5,7, 33,47, 52, 53, 56, 84, 94, 97, 99 Substituents, 15, 16, 20, 24 (also see groups), -acyclic, 37 -bivalent, 41 -identical, 35

-of acid radicals, 54, 55 -of alcohols, 52

-of heterocycles, 92, 93 -of ketones, 64, 65 Unsaturation, 5, 6, 7, 16, 20, 44, 149 Urea, 63, 68 Zwitter ions, 73

Nomenclature of

Organic Compounds

Revised Edition

BC ral Nomenclature of Organic Compounds follows recommendations of IUPAC in naming organic compounds, carbocations etc. The book aimed at the Undergraduate Students, illustrates the rules of various nomenclature with simple examples. A diagrammatic presentation is also given to create interest in the topic alongwith a comparison of different nomenclature operations for some compounds with some typical structures. A number of examples are solved in a systematic step-by-step approach.

KEY FEATURES: @ Exercises with various types of problems including multiple-choice question. @ Hints are given for solutions to many selected problems for exercises.

ISBN

974-1-842b5-482-8

Alpha Science International Ltd.

www.alphasci.com

7°

74818

He

bBS48

|