Chapter 7.15, Problem 31P

Interpretation Introduction

(a)

Interpretation: The compound from the given pair that reacts faster in nucleophilic substitution is to be identified.

Concept introduction: Nucleophilic substitution reaction takes place by two mechanisms, ${\text{S}}_{\text{N}}\text{1}$ and ${\text{S}}_{\text{N}}\text{2}$. In ${\text{S}}_{\text{N}}\text{1}$ mechanism, formation of carbocation takes place by removal of halide and then nucleophile attack on that carbocation. However in ${\text{S}}_{\text{N}}\text{2}$ mechanism, removal of halide and attack of nucleophile takes place simultaneously. The presence of good leaving group increases the rate of both ${\text{S}}_{\text{N}}\text{1}$ and ${\text{S}}_{\text{N}}\text{2}$ reactions.

Interpretation Introduction

(b)

Interpretation: The compound form the given pair that reacts faster in nucleophilic substitution is to be identified.

Concept introduction: Nucleophilic substitution reaction takes place by two mechanisms, ${\text{S}}_{\text{N}}\text{1}$ and ${\text{S}}_{\text{N}}\text{2}$. In ${\text{S}}_{\text{N}}\text{1}$ mechanism, formation of carbocation takes place by removal of halide and then nucleophile attack on that carbocation. However in ${\text{S}}_{\text{N}}\text{2}$ mechanism, removal of halide and attack of nucleophile takes place simultaneously. The presence of good leaving group increases the rate of both ${\text{S}}_{\text{N}}\text{1}$ and ${\text{S}}_{\text{N}}\text{2}$ reactions.

Interpretation Introduction

(c)

Interpretation: The compound from the given pair that reacts faster in nucleophilic substitution is to be identified.

Concept introduction: Nucleophilic substitution reaction takes place by two mechanisms, ${\text{S}}_{\text{N}}\text{1}$ and ${\text{S}}_{\text{N}}\text{2}$. In ${\text{S}}_{\text{N}}\text{1}$ mechanism, formation of carbocation takes place by removal of halide and then nucleophile attack on that carbocation. However in ${\text{S}}_{\text{N}}\text{2}$ mechanism, removal of halide and attack of nucleophile takes place simultaneously. The presence of good leaving group increases the rate of both ${\text{S}}_{\text{N}}\text{1}$ and ${\text{S}}_{\text{N}}\text{2}$ reactions.

Interpretation Introduction

(d)

Interpretation: The compound from the given pair that reacts faster in nucleophilic substitution is to be identified.

Concept introduction: Nucleophilic substitution reaction takes place by two mechanisms, ${\text{S}}_{\text{N}}\text{1}$ and ${\text{S}}_{\text{N}}\text{2}$. In ${\text{S}}_{\text{N}}\text{1}$ mechanism, formation of carbocation takes place by removal of halide and then nucleophile attack on that carbocation. However in ${\text{S}}_{\text{N}}\text{2}$ mechanism, removal of halide and attack of nucleophile takes place simultaneously. The presence of good leaving group increases the rate of both ${\text{S}}_{\text{N}}\text{1}$ and ${\text{S}}_{\text{N}}\text{2}$ reactions.