Chapter 9, Problem 9.61P

Interpretation Introduction

(a)

Interpretation:

It is to be suggested how the given reaction could be carried out with the focus on the nucleophile and the choice of the solvent.

Concept introduction:

Nucleophilic substitution reactions can occur via two mechanisms, ${\text{S}}_{\text{N}}{\text{2 or S}}_{\text{N}}\text{1}$. The mechanism that prevails is determined by a number of factors – the type of the electrophilic carbon, nature of the leaving group, the strength and concentration of the nucleophile, and the nature of the solvent. When the substrate is the same, the mechanism is determined by the strength and concentration of the nucleophile and the nature of the solvent.

A strong nucleophile and polar aprotic solvent favor the ${\text{S}}_{\text{N}}\text{2}$ mechanism. A weak nucleophile or a strong nucleophile at low concentrations and a polar protic solvent favor the ${\text{S}}_{\text{N}}\text{1}$ mechanism.

When the electrophilic carbon is chiral, the ${\text{S}}_{\text{N}}\text{2}$ mechanism results in an inversion of the configuration. On the other hand, the ${\text{S}}_{\text{N}}\text{1}$ mechanism leads to racemization.

Interpretation Introduction

(b)

Interpretation:

Concept introduction:

It is to be suggested how the given reaction could be carried out with the focus on the nucleophile and the choice of the solvent.

Concept introduction:

Nucleophilic substitution reactions can occur via two mechanisms, ${\text{S}}_{\text{N}}{\text{2 or S}}_{\text{N}}\text{1}$. The mechanism that prevails is determined by a number of factors – the type of the electrophilic carbon, nature of the leaving group, the strength and concentration of the nucleophile, and the nature of the solvent. When the substrate is the same, the mechanism is determined by the strength and concentration of the nucleophile and the nature of the solvent.

A strong nucleophile and polar aprotic solvent favor the ${\text{S}}_{\text{N}}\text{2}$ mechanism. A weak nucleophile or a strong nucleophile at low concentrations and a polar protic solvent favor the ${\text{S}}_{\text{N}}\text{1}$ mechanism.

When the electrophilic carbon is chiral, the ${\text{S}}_{\text{N}}\text{2}$ mechanism results in an inversion of the configuration. On the other hand, the ${\text{S}}_{\text{N}}\text{1}$ mechanism leads to racemization.