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Characteristic (Functional) Groups

R-3.1.1 Suffixes denoting multiple bonds

The presence of one or more double or triple bonds in an otherwise saturated parent hydride (except for parent hydrides with Hantzsch-Widman names) is denoted by changing the "-ane" ending of the name of a saturated parent hydride to one of the following:

One Two Three etc.
Double bond -ene -adiene -atriene etc.
Triple bond -yne -adiyne -atriyne etc.

The presence of both double and triple bonds is similarly denoted by endings such as "-enyne", "-adienyne", "-enediyne", etc. Numbers as low as possible are given to double and triple bonds as a set, even though this may at times give "-yne" a lower number than "-ene". If a choice remains, preference for low locants is given to the double bonds. Only the lower locant for a multiple bond is cited except when the numerical difference between the two locants is greater than one, in which case the higher-numbered locant is cited in parentheses (see R-0.1.4).

Examples to R-3.1.1

Use of these ending is further illustrated in Sections R-4 and R-5 (see also the 1979 edition of the IUPAC Nomenclature of Organic Chemistry , Rule A-3).

R-3.1.2 Hydro prefixes
R-3.1.3 Dehydro prefixes
R-3.1.4 Substituent prefix names for unsaturated/saturated parent hydrides

This HTML reproduction is as close as possible to the published version [see IUPAC, Commission on Nomenclature of Organic Chemistry. A Guide to IUPAC Nomenclature of Organic Compounds (Recommendations 1993), 1993, Blackwell Scientific publications, Copyright 1993 IUPAC]. If you need to cite these rules please quote this reference as their source.

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