Question

Give the name and structrues of six `C` atom cyclic diene with lowest molecular mass that shows only geometrical isomers (diastereomers) and not optical isomers.

Answer 1

In a cyclic compound, cumulative diene is not possible.
Case I :One double bond in a ring is conjugated with another double bond outside the ring.

Case II: One double bond in a ring in isolated position with another double bond outside the ring

Case III: Two double bonds in the ring in isolated position.

If the `Me` groups are placed at the double bond, none of them shows geometrical isomerism.

Case IV: Two double bounds in the ring in conjugation it also does not show geometrical isomerism.