Chapter 8, Problem 8.63P

Interpretation Introduction

Interpretation:

The reasonable and detailed mechanism under the acidic condition that shows racemization at alpha carbon is to be drawn.

Concept introduction:

An ${\text{S}}_{\text{N}}\text{1}$ reaction is a unimolecular nucleophilic substitution reaction and is a two-step reaction. In the first step, the leaving group breaks the bond with carbon and forms a carbocation. In the second step, the nucleophile attacks the carbocation and forms a racemic mixture. The stereochemistry of the product depends upon the attack on the nucleophile.

In a reasonable mechanism, the oxygen with lone pairs is protonated prior to the ${\text{S}}_{\text{N}}\text{1}$ reaction. In the proton transfer reaction, the elementary steps are incorporated into this reaction. Under the acidic conditions, the equilibrium concentration of the basic species is very small. It is a very fast reaction and incorporated before and after elementary reactions.