Chapter 12, Problem 12.56P

Interpretation Introduction

Interpretation: The possible structures of dictyopterene D are to be identified.

Concept introduction: In presence of ozone and ${\text{CH}}_{\text{3}}{\text{SCH}}_{\text{3}}$, oxidative cleavage occurs. In oxidative cleavage both the sigma and pi bond of the alkene is broken and two carbonyl compounds are formed. Aldehydes or ketones are depending upon substituents. When ozone is added to the alkene, unstable intermediate molozonide is formed which rearranges to ozonide. This ozonide is reduced to form two carbonyl compounds in presence of ${\text{CH}}_{\text{3}}{\text{SCH}}_{\text{3}}$.

The addition of ${\text{H}}_{\text{2}}$ in presence of catalyst is known as catalytic hydrogenation reaction. This is a syn addition. Alkene is reduced to alkane. In this reaction weak pi bond of alkene and sigma bond between ${\text{H}}_{\text{2}}$ is broken and two $\text{C}-\text{H}$ bonds are formed.