Basic Organic Nomenclature
4. Functional Groups with Suffix Only
The -yne name is given to the C,C triple bond function. The group is linear, as you have seen
from the models in the introduction, and may appear anywhere in the carbon chain, thus often requiring
a locant (position identifier).
Study the following examples of straight-chain alkynes:
Note from the above names that the locant is only the first
number of the two which identify the position of the triple bond. Thus although the triple bond in
hex-3-yne is between carbons numbered 3 and 4 in the chain, only the first is required to
position the triple bond, the second being understood to be the next higher number.
Changes and additions to the rules for naming compounds are thus:
Note also the position of the locant in the name. IUPAC now puts the locant immediately in front of the group that it is positioning: hex-3-yne rather than 3-hexyne.
Examine the following names for other alkynes:
Note the last example, which is named as a heptyne: the longest continuous chain of carbons is eight, but this does not contain the functional group.
If more than one C,C triple bond is present, the name can be produced by using diyne, triyne, etc:
Review Functional Groups with Suffix Only I Introduction
Next page : Functional Groups with Suffix Only III Alkenes.
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