Chapter 10, Problem 34P

Interpretation Introduction

(a)

Interpretation: The constitutional isomer formed by the reaction of the given alkene with ${\text{Br}}_{\text{2}}$ is to be predicted.

Concept introduction: The addition of Halogens to alkenes is a stereospecific reaction. The resultant product is meso compound, if alkene is cis and addition of halogen is syn addition. If addition of halogen is anti, then the resultant products are racemic mixture. In case of trans alkene, the resultant product is meso, if addition of halogen is anti. The resultant products are racemic mixture, if the addition of halogen is syn.

Interpretation Introduction

(b)

Interpretation: The constitutional isomer formed by the reaction of the given alkene with ${\text{Br}}_{\text{2}}/{\text{H}}_{\text{2}}\text{O}$ is to be predicted.

Concept introduction: The reaction of alkene with halogen and water results in the formation of halohydrin product.

The general steps for the formation of halohydrin are stated below:

Ø The first step is the attack of halide ion to form a halonium ion.

Ø The second step is the attack of water from back side to opens the halonium ion.

Ø The last step is deprotonation to give the halohydrin product.

Interpretation Introduction

(c)

Interpretation: The constitutional isomer formed by the reaction of the given alkene with ${\text{Br}}_{\text{2}}/{\text{CH}}_3\text{OH}$ is to be predicted.

Concept introduction: The reaction of alkene with halogen and methanol results in the formation of methoxy product.

The general steps for the formation of desired product are stated below:

Ø The first step is the attack of halide ion to form a halonium ion.

Ø The second step is the attack of methanol from back side to open the halonium ion.

Ø The last step is deprotonation to give the desired product.