Chapter 12, Problem 12.57P

Interpretation Introduction

Interpretation:

The mechanism for the given Simmons-Smith reaction is to be completed.

Concept introduction:

The Simmons-Smith reaction is an addition of CH₂ across the double bond of the alkene to form a cyclopropane ring in the product. The mechanism for this transformation is very similar to that for epoxidation of an alkene by peracids. It involves a concerted action, with the bond making and bond breaking process occurring simultaneously.

$\text{Zn-C, C-I}$ and $\text{C=C}$ bonds are broken, and simultaneously, new $\text{C-C}$ and $\text{Zn-I}$ bonds are formed.