Chapter 21, Problem 21.4P

Interpretation Introduction

Interpretation:

The structure of an amide that must exist in $E$ conformation is to be stated.

Concept introduction:

$E$ or $Z$ configuration is dependent on the atomic number of the atoms attached to the double bond. If the higher priority atoms are present on the same side of the double bond, then it is assigned as $Z$ configuration. If the higher priority atoms present on the opposite side of the double bond then it is assigned as $E$ configuration.