Chapter 8, Problem 8.76P

Interpretation Introduction

Interpretation:

Chemist’s hypothesis that the given reaction proceeds by an ${\text{S}}_{\text{N}}\text{2}$ mechanism is to be evaluated on the basis of the analysis of products obtained with ${}^{\text{18}}\text{O}$ labeled hydroxide and water.

Concept introduction:

An ${\text{S}}_{\text{N}}\text{2}$ mechanism is a single step mechanism. The incoming group forms a bond with the carbon at the reaction center with the bond to the leaving group breaking simultaneously to prevent exceeding valence shell octet on the carbon. If an isotopically labeled nucleophile is used, the labeled atom, generally the one which acts as lone pair donor, is incorporated in the product. It does not form a bond with the leaving group.