Characteristic Groups

Principal Group for Citation as Suffix Rule C-10.3

10.3 - If any characteristic groups other than those in Table C-I are present, one kind must be cited as suffix, but only one kind. That kind of group is termed the principal group. When a compound contains more than one kind of group not listed in Table C-I, the principal group is that which characterizes the class occurring as high as possible in Table C-II; all other characteristic groups are then cited as prefixes. Some suffixes and prefixes to be used with the general classes given in Table C-II are listed in Table C-III. Further details will be found in Subsections C-1 to C-9. Multiplying affixes and locants are added as necessary. If, but only if, the complete suffix (that is, the suffix itself plus its multiplying affix, if any) begins with a vowel, a terminal "e" (if any) of the preceding parent name is elided. Elision or retention of the terminal "e" is independent of the presence of numerals between it and the following letter.

Examples to Rule C-10.3

Suffix for principal group, OH: -ol
Parent name for CH3CH3: Ethane
Full names: Ethanol

Principal group of class higher in Table C-II: >(C)=O, denoted by suffix -one.
Parent name: Heptane
Name based on: Heptanone
Full name: 7-Hydroxy-2-heptanone

Suffix: -ol
Parent name: Pentane, altered to pentene for unsaturation (see Rule A-3.1)
Full name: 4-Penten-1-ol

Principal Group for Citation as Suffix


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