Chapter 19, Problem 19.59P

Interpretation Introduction

(a)

Interpretation:

The reagent lithium dialkylcuprate that would be necessary to carry out the given transformations is to be drawn.

Concept introduction:

A new carbon-carbon bond forming reaction involves coupling reaction. In this reaction, lithium dialkylcuprate also called as Gilman reagent is used. The reagent lithium dialkylcuprate has general formula ${\text{R}}_{\text{2}}\text{CuLi}$, which acts as relatively weak ${\text{R}}^{\text{-}}$ nucleophile in the conjugate addition to $\text{α,β-unsaturated}$ aldehydes, ketones, and other polar $\text{π}$ bonds. In the coupling reaction, two alkyl groups are joined together, one from the alkyl halide $\left(\text{RX}\right)$ and other from dialkylcuprate $\left({\text{R’}}_{\text{2}}\text{CuLi}\right)$. In the coupling reaction between alkyl halide and lithium dialkylcuprate, the $\text{R’}$ group from the ${\text{R’}}_{\text{2}}\text{CuLi}$ occupies the position of the halogen atom in the alkyl halide.

Interpretation Introduction

(b)

Interpretation:

The reagent lithium dialkylcuprate that would be necessary to carry out the given transformations is to be drawn.

Concept introduction:

A new carbon-carbon bond forming reaction involves coupling reaction. In this reaction, lithium dialkylcuprate also called as Gilman reagent is used. The reagent lithium dialkylcuprate has general formula ${\text{R}}_{\text{2}}\text{CuLi}$ which acts as relatively weak ${\text{R}}^{\text{-}}$ nucleophile in the conjugate addition to $\text{α,β-unsaturated}$ aldehydes, ketones, and other polar $\text{π}$ bonds. In the coupling reaction, two alkyl groups are joined together, one from the alkyl halide $\left(\text{RX}\right)$ and other from dialkylcuprate $\left({\text{R’}}_{\text{2}}\text{CuLi}\right)$. In the coupling reaction between alkyl halide and lithium dialkylcuprate, the $\text{R’}$ group from ${\text{R’}}_{\text{2}}\text{CuLi}$ occupies the position of the halogen atom in the alkyl halide.