Chapter 14, Problem 14.63P

Interpretation Introduction

(a)

Interpretation:

For the given pair of substrates, it is to be explained which one will undergo an $S_{N}1$ reaction faster.

Concept introduction:

In ${\text{S}}_{\text{N}}\text{1}$ reaction, the first, rate-determining step involves removal of the leaving group to form a carbocation. The stability of the carbocation decides the speed it is formed. Since this is the rate-determining step, the overall reaction rate depends on the stability of the carbocation. The more stable the carbocation, the faster the reaction rate.

The stability of a carbocation depends mainly on two factors, the number of substituents on the same carbon and the number of atoms over which the charge may be delocalized. The higher the number of substituents on the carbocation, the more its stability. The more the number of atoms over which the charge is delocalized, the higher the stability o the carbocation.

Interpretation Introduction

(b)

Interpretation:

For the given pair of substrates, it is to be explained which one will undergo an $S_{N}1$ reaction faster.

Concept introduction:

In ${\text{S}}_{\text{N}}\text{1}$ reaction, the first, rate-determining step involves removal of the leaving group to form a carbocation. The stability of the carbocation decides the speed it is formed. Since this is the rate-determining step, the overall reaction rate depends on the stability of the carbocation. The more stable the carbocation, the faster the reaction rate.

The stability of a carbocation depends mainly on two factors, the number of substituents on the same carbon and the number of atoms over which the charge may be delocalized. The higher the number of substituents on the carbocation, the more its stability. The more the number of atoms over which the charge is delocalized, the higher the stability o the carbocation.