Chapter 19, Problem 19.46P

Interpretation Introduction

Interpretation:

The given transformation is to be carried out using ${{\text{(CH}}_{\text{3}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}\text{)}}_{\text{2}}\text{CuLi}$ as the only other carbon source.

Concept introduction:

Lithium dialkylcuprates ${\text{R}}_{\text{2}}\text{CuLi}$ are weaker nucleophiles and selectively undergo $\text{1, 4-}$ addition with the conjugated carbonyl compounds. The one $\text{R}$ group from ${\text{R}}_{\text{2}}\text{CuLi}$ forms a bond with the $\text{β}$ carbon of the conjugated carbonyl compound.

The carbonyl groups of aldehyde or ketone can be reduced to methylene, i.e., $\text{C=O}$ to ${\text{CH}}_{\text{2}}$, using the reactions like Wolff-Kishner reduction, Clemmensen, and Raney-nickel. If a carbonyl compound has acid sensitive other functional groups or the functional groups that are susceptible to reaction with nucleophilic thiols ($\text{RSH}$) or with ${\text{H}}_{\text{2}}$ in the presence of a metal catalyst, then the Woff-Kishner reduction is preferable. The reagent used for Wolff-Kishner reduction is ${\text{NH}}_{\text{2}}{\text{NH}}_{\text{2}}\text{, KOH/}\Delta$.