Chapter 12, Problem 12.43P

Interpretation Introduction

(a)

Interpretation: The product formed when A is treated with $\text{mCPBA}$ is to be predicted.

Concept introduction: In the presence of peroxide, alkene is oxidized to epoxide. This is known as epoxidation. This is a syn addition. The weak pi bond of alkene and weak $\text{O}-\text{O}$ bond of peroxide are broken and two new $\text{C}-\text{O}$ bonds are formed. Breaking of bonds and formation of bonds takes place in single step. $\text{mCPBA}$ is $\text{meta-chloroperoxybenzoic}\text{acid}$.

Interpretation Introduction

(b)

Interpretation: The product formed when A is treated with ${\text{Br}}_{\text{2}},{\text{H}}_{\text{2}}\text{O}$ followed by base is to be predicted.

Concept introduction: The reaction between bromine and alkene proceeds via the formation of cyclic bromonium intermediate. The reaction of bromine in water is an anti addition on alkene. This is a regioselective reaction, the hydroxyl group adds to the more substituted carbon of the double bond.