Chapter 10, Problem 10.7P

Interpretation Introduction

Interpretation: The given compound $11-cis-\text{retinal}$ is to be labeled as $E$ or $Z$.

Concept introduction: The use of prefix E or Z depends upon the location of the higher priority groups. When two higher priority groups are present on the opposite side then it is an $E$ isomer, whereas when two higher priority groups are present on the same side then it is a $Z$ isomer. The priority order depends upon the atomic number of the elements.