Answer
The IUPAC names of the compounds are:
(a) 3-Methylcyclohexene
(b) 1,5-Dimethylcyclopentene
(c) 1-Ethylcyclobuta-1,3-diene
(d) 1,2-Dimethylcyclohexa-1,4-diene
(e) 5-Methylcyclohexa-1,3-diene
(f) Cycloocta-1,5-diene
Work Step by Step
1. We number the cycloalkenes in such a manner that the double bond is between the first and the second carbon of the cycloalkene.
2. In case substituents are present, they are assigned the lowest number/locant.
3. The suffix -diene is used whenever there are two double bonds in the cycloalkene ring. Also their positions need to be indicated.
