Chapter 26, Problem 26.25P

Interpretation Introduction

Interpretation:

Why the second and subsequent double bonds form more quickly in the series of reactions shown in Equation 26-42 is to be explained.

Concept introduction:

In molecules containing multiple double bonds, the stability depends on the number of single bonds that separate the double bonds. Conjugated double bonds (separated by one single bond) are more stable than isolated double bonds (separated by more than one single bond) and cumulated double bonds (no separation).

As the extent of conjugation increases, so does the stability of the molecule. As a result, any reaction that increases the extent of conjugation occurs relatively easily.