Chapter 19.SE, Problem 62AP

Interpretation Introduction

a)

Interpretation:

How to prepare cyclohexene from 2-cyclohexenone is to be stated.

Concept introduction:

Wolf-Kishner reduction rection can be used to prepare cyclohexene from 2-cyclohexenone.

To state:

How to prepare cyclohexene from 2-cyclohexenone.

Interpretation Introduction

b)

Interpretation:

How to prepare 3-phenylcyclohexanone from 2-cyclohexenone is to be stated.

Concept introduction:

By treating 2-cyclohexenone with lithiumdiphenylcopper and acidifying the product formed 3-phenylcyclohexanone can be prepared, as the organolithiumcopper reagents are good reagents for the conjugate addition to α,β- unsaturated ketones.

To state:

How to prepare 3-phenylcyclohexanone from 2-cyclohexenone.

Interpretation Introduction

c)

Interpretation:

How to prepare the ketoacid shown from 2-cyclohexenone is to be stated.

Concept introduction:

An easily oxidizable group is introduced to C₃ of 2-cyclohexenone by a conjugate addition using lithiumdialkylcopper reagent. The resulting product can then be oxidized to a carboxylic acid by acidified KMnO₄.

To state:

How to prepare the keto acid shown from 2-cyclohexenone.

Interpretation Introduction

d)

Interpretation:

How to prepare methylcyclohexane from 2-cyclohexenone (two ways) is to be shown.

Concept introduction:

An alkyl group can be introduced into 2-cyclohexenone by treating it with lithiumdialkyl reagent(conjugate addition takes place). The keto group can be reduced to CH₂ by Wolff-Kishner reduction.

Another way is to replace the C =O in 2-cyclohexenone by C =CH₂ by a Wittig reaction first and then reducing it to C-CH₃ by H₂, Pd/C.

To state:

How to prepare methylcyclohexane from 2-cyclohexenone.