Chapter 13, Problem 13.16P

Interpretation Introduction

Interpretation:

The precursor needed for the reaction corresponding to the transform shown is to be drawn with appropriate stereochemical configuration.

Concept introduction:

An ${\text{S}}_{\text{N}}\text{2}$ reaction is a single-step reaction. The nucleophile attacks the electron-poor carbon in the substrate and displaces the leaving group. Since the nucleophile starts to form a bond with the carbon before the leaving group has broken off, it must attack from a direction opposite to that of the leaving group. This requirement makes an ${\text{S}}_{\text{N}}\text{2}$ reaction stereospecific, with an inversion of the configuration at the reaction center.