Chapter 12, Problem 49P

Interpretation Introduction

(a)

Interpretation: Compound A is to be identified.

Concept introduction: In the 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. 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 ${\text{CH}}_{\text{3}}{\text{SCH}}_{\text{3}}$.

Interpretation Introduction

(b)

Interpretation: Compounds B and C are to be identified.

Concept introduction: Terminal alkynes can be converted into internal alkynes by forming new $\text{C}-\text{C}$ bond. This bond is formed by treatment of alkyne by strong base and alkyl halide.

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