Chapter 9, Problem 9.67P

Interpretation Introduction

Interpretation:

The complete, detailed mechanism that accounts for the formation of each of the given products when the reaction mixture in Problem 9.66 is heated is to be given.

Concept introduction:

The unimolecular elimination (E1) reactions consists of two steps. First, the leaving group leaves, generating a carbocation intermediate, which can be rearranged via 1, 2-hydride shift or 1, 2-methyl shift. If the resulting carbocation intermediate has conjugated multiple bonds, the carbocation can be resonance stabilized. Increasing the temperature of the reaction mixture or heating the reaction mixture tends to promote the elimination reaction more than the substitution reaction. In the second step, the H+ is eliminated with the aid of a base to yield a double bond. Because E1 reaction takes place in two steps, both E and Z alkenes are produced.