Chapter 6, Problem 57CP

(A)

Interpretation Introduction

Interpretation:

The carbon atom which is migrating in the given reaction has to be identified and a mechanism should be provided for this rearrangement.

Concept Introduction:

Mechanism of the reaction is the step-by-step description of the process by which reactants are changed into products.

Curved arrows show the bonds that are formed and the bonds that are broken in a reaction.

Curved arrows used to understand a reaction mechanism.

Curved arrows are drawn to show how the electrons move as new covalent bonds are formed existing covalent bonds are broken.

Each arrow represents the simultaneous movement of two electrons from a nucleophile towards an electrophile.

Rearrangements will always occur when an alkyl group or hydrogen can shift to form a more stable carbocation. There are mainly two types of rearrangement shifts and they are,

$\begin{array}{l}\text{1, 2-methyl shift}\hfill \\ \text{1, 2-hydride shift}\hfill \end{array}$

(b)

Interpretation Introduction

Interpretation:

The diastereomeric carbocation that is not formed in the given reaction has to be drawn and the reason should be provided for its lack of formation.

Concept Introduction:

Chiral center: A chiral center is defined as the tetrahedral carbon atom in an organic molecule that is connected to four non-identical groups/substituents. It is sometimes known as a stereo genic center.

Diastereomers: A compound which is non-superimposable and non-mirror image is called enantiomers

Chiral center: A chiral center is defined as the tetrahedral carbon atom in an organic molecule that is connected to four non-identical groups/substituents. It is sometimes known as a stereo genic center.

Cycloalkanes are less flexible than open-chain alkanes and so they have less conformational freedom.

(C)

Interpretation Introduction

Interpretation:

In the given reaction a tertiary carbocation is rearranging to give a different tertiary carbocation, the driving force for this process has to determined and explained.

Concept Introduction:

Chiral center: A chiral center is defined as the tetrahedral carbon atom in an organic molecule that is connected to four non-identical groups/substituents. It is sometimes known as a stereo genic center.

Diastereomers: A compound which is non-superimposable and non-mirror image is called enantiomers

Chiral center: A chiral center is defined as the tetrahedral carbon atom in an organic molecule that is connected to four non-identical groups/substituents. It is sometimes known as a stereo genic center.

Cycloalkanes are less flexible than open-chain alkanes and so they have less conformational freedom.