Chapter 6, Problem 81P

(a)

Interpretation Introduction

Interpretation:

The major products of the following reactions should be determined.

Concept Introduction:

Halogen addition to an alkene:

The addition reaction of halides to alkenes leads to the formation of vicinal dihalide as the product. The two halogens will be on the adjacent carbons.

Mainly ${\text{Br}}_{\text{2}}\text{and}{\text{Cl}}_{\text{2}}$ undergo addition reaction with alkenes and the reaction is carried out in an inert solvent such as dichloromethane.

In general, the reaction can be shown as below.

When the bromine approaches the alkene, one bromine accepts the electrons from alkene and give them to the other bromine and a cyclic bromonium ion intermediate is formed.

The formed unstable intermediate reacts with ${\text{Br}}^{\text{-}}$ and the product is formed.

(b)

Interpretation Introduction

Interpretation:

The major products of the following reactions should be determined.

Concept Introduction:

Halogen addition to an alkene:

The addition reaction of halides to alkenes leads to the formation of vicinal dihalide as the product. The two halogens will be on the adjacent carbons.

Mainly ${\text{Br}}_{\text{2}}\text{and}{\text{Cl}}_{\text{2}}$ undergo addition reaction with alkenes and the reaction is carried out in an inert solvent such as dichloromethane.

In general, the reaction can be shown as below.

When the bromine approaches the alkene, one bromine accepts the electrons from alkene and give them to the other bromine and a cyclic bromonium ion intermediate is formed.

The formed unstable intermediate reacts with ${\text{Br}}^{\text{-}}$ and the product is formed.