Chapter 11, Problem 11.21P

Interpretation Introduction

Interpretation:

The mechanisms for the transformation of neryl pyrophosphate to $\text{α-terpeniol}$ and terpin hydrate are to be drawn.

Concept introduction:

Neryl pyrophosphate contains two isoprene units linked head to tail. It undergoes heterolysis to produce a resonance stabilized primary carbocation. The presence of a double bond five bonds away from the primary carbocation leads to cyclization. The double bond is a relatively electron-rich region and acts as a nucleophile. The $\text{π}$-bond pair moves toward the carbocation to form a stable six-membered ring.