Question

The geometrical isomerism is shown by :

• A.
• B.
• C.
• D.

Answer 1

The correct option is D

For an alkene system, if the groups acoss $C=C$ bond are not same, it leads to more than one spatial arrengements of groups acoss the double bond and are called geometrical isomers.

Conditions for Geometrical Isomerism:
1. Free rotation must be restricted
2. Both the terminals of the system must be attached with different atoms/groups.

For options (a) and (b), there are two same $H$ atoms present on terminal $C$ attached with double bond. So, there is no possibility of different arrangements in (a) and (b) and hence no geometrical isomers are possible. In option (c), the cyclic $C$ containing double bond has symmetrical arrangements i.e. both its groups are same. So, no possibility of geometrical isomers. For option (d), there are different groups present on both $C$ involved in double bond and hence it leads to geometrical isomers.
Hence, (d) is correct.