Enynes

Basic IUPAC Organic Nomenclature

The term enyne simply implies the presence of both an alkene and an alkyne.
Enynes are named in a similar manner to alkenes, alkynes and polyenes.

The root name is based on the longest chain containing both ends of the alkene and alkyne units.
The alkene suffix "ene" minus the last "e" is inserted after the root with its locant before the root.
The alkyne suffix, "yne" is added at the end with its locant preceding it.
Hence alkene + alkyne = enyne.
The chain is numbered in accord with the first point of difference rule to either the alkene or alkyne units the lowest possible locant.
The locant for the lowest numbered carbon of the alkene or alkyne is used in the name.
If there is a choice, then the C=C takes priority and is given the lowest locant.

hex-1-en-4-yne

CH₂=CHCH₂C≡CCH₃

cis-hex-4-en-1-yne
or
(Z)-hex-4-en-1-yne

CH₃CH=CHCH₂C≡CH

Functional groups : alkene and alkyne, therefore suffix = -en and -yne
The longest continuous chain is C5 therefore root = pent
The first point of difference fails since C=C and C≡C are equally distant from the ends.
Therefore the C=C takes priority and requires that we number from the left as drawn
Locant for C=C is therefore 1-
Locant for C≡C is therefore 4-

pent-1-en-4-yne

CH₂=CHCH₂C≡CH