Chapter 10.4, Problem 7P

Interpretation Introduction

a)

Interpretation:

The product expected when 5-methylcycloheptene reacts with NBS is to be shown. If more than one product is possible the structures of all of them are to be shown.

Concept introduction:

NBS is used mainly for allylic bromination. An unsymmetrical alkene will lead to a mixture of products as two different allyl radicals will be produced as a result of delocalization. The two products are not formed in equal amounts because the intermediate allylic radical is not symmetrical and the reaction at two ends will not take place to the same extent. Reaction at less hindered primary side is more favored.

To show:

The structures of all the products expected when 5-methylcycloheptene reacts with NBS.

Interpretation Introduction

b)

Interpretation:

The product expected when 2-methyl-3-hexene reacts with NBS is to be shown. If more than one product is possible the structures of all of them are to be shown.

Concept introduction:

NBS is used mainly for allylic bromination. An unsymmetrical alkene will lead to a mixture of products as two different allyl radicals will be produced as a result of delocalization. The two products are not formed in equal amounts because the intermediate allylic radical is not symmetrical and the reaction at two ends will not take place to the same extent. Reaction at less hindered primary side is more favored.

To show:

The structures of all the products expected when 2-methyl-3-hexene reacts with NBS.