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Substitutive Nomenclature

General Procedure Rule C-16.3

16.31 - Simple prefixes (that is, those for unsubstituted substituents and for atoms) are first arranged alphabetically; multiplying affixes (if necessary) are then inserted and do not alter the alphabetical order already attained.

Examples to Rule C-16.31

(Letters causing the alphabetical arrangement in this and similar names are printed in bold type.)

16.32 - For this method subtractive prefixes (such as anhydro, dehydro, demethyl: see Subsection C-0.4) may be alphabetized among those arising from substitutive nomenclature or treated as non-detachable. they are considered to begin with the first letter of the complete prefix.

Example to Rule C-16.32

16.33 - Hydro prefixes may be treated as detachable and arranged in alphabetical order among other detachable prefixes or they may be treated as non-detachable from the parent compound or radical.

Example to Rule C-16.33

Detachable: 1,2,3,4-Tetrahydro-4-oxo-1-naphthoic acid
Non-detachable: 4-Oxo-1,2,3,4-tetrahydro-1-naphthoic acid

16.34 - The name of prefix for a substituted substituent is considered to begin with the first letter of its complete name.

Examples to Rule C-16.34

(Dimethylpentyl as a complete substituent is alphabetized under "d").

(In the substituted radical, ethyl and methyl are first alphabetized before ureido, and the whole is then considered to begin with its first letter "e".)

(The first point of difference, printed bold, is decisive.)

16.35 - When two or more prefixes are composed of identical words, priority for citation is given to that radical which contains the lowest locant at the first-cited point of difference.

Example to Rule C-16.35

16.36 - o- (ortho-), m- (meta-), and p- (para-) Substituted substituents, if otherwise identical, are arranged in that order (the same as that of their numerical equivalents, 2-, 3-, and 4-, respectively).

Example to Rule C-16.36


This HTML reproduction of Sections A, B and C of IUPAC "Blue Book" is as close as possible to the published version [see Nomenclature of Organic Chemistry, Sections A, B, C, D, E, F, and H, Pergamon Press, Oxford, 1979. Copyright 1979 IUPAC.] If you need to cite these rules please quote this reference as their source.

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