Chapter 12, Problem 12.67P

Interpretation Introduction

Interpretation: Synthesis of $\text{1-phenyl-5-methylhexane}\left[{\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\left({\text{CH}}_{\text{2}}\right)}_{\text{4}}\text{CH}{\left({\text{CH}}_{\text{3}}\right)}_{\text{2}}\right]$ from acetylene, alkyl halides and other required reagents is to be devised.

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 alkene and sigma bond between ${\text{H}}_{\text{2}}$ is broken and four $\text{C}-\text{H}$ bonds are formed.