Answer
The IUPAC name of the compounds are:
(a) 1,2-Dimethylcyclohexene
(b) 4,4-Dimethylcycloheptene
(c) 3-Isopropylcyclopentene
Work Step by Step
While naming cycloalkenes, the following rules have to be followed:
1. Start numbering the cycloalkene in such a way that the double bond is between carbon 1 and carbon 2.
2. The substituents (branches) are given the lowest possible number.
3. The branches are written as prefixes to the name of the cyclic structure.
For example in (a), the cyclic alkene has six carbon atoms. The carbons are numbered in such a way that the double bond is between C1 and C2. The two methyl groups (branches) are present at C1 and C2 and thus the compound is named 1,2-Dimethylcyclohexene.
