Chapter 11.3, Problem 1RC

Interpretation Introduction

Interpretation:

The reason for geometrical isomerism is impossible in benzene has to be explained.

Concept introduction:

Cis–trans isomerism (or) geometric isomerism or configurational isomerism:

The two similar groups (or higher priority groups) are in same side in double bond of alkenes is called as cis isomer (or Z-isomer). Two similar groups (or higher priority groups) are opposite side in double bond of alkenes is called as trans isomer (or E-isomer).

Example:

Geometrical isomerism is a kind of stereoisomerism which arises due to restricted rotation of $\text{C=C}$ bond in a molecule.  It is also known as cis-trans isomerism or E-Z isomerism.