Chapter 10, Problem 10.19P

Interpretation Introduction

Interpretation:

The complete, detailed mechanism for the formation of the unsymmetric ether is to be drawn.

Concept introduction:

The synthesis of an ether via the dehydration of an alcohol is useful only when the target is a symmetric ether. The ether formation can take place via nucleophilic substitution under acidic conditions. In the first step, the $\text{OH}$ group is protonated to become a very good leaving group (i.e., ${\text{H}}_{\text{2}}\text{O}$). Steps 2 and 3 form the two-step ${\text{S}}_{\text{N}}\text{1}$ reaction. The water leaves in a heterolysis step, followed by the attack of the nucleophile in a coordination step. In Step 4, another proton transfer produces the uncharged ether.