Chapter 24.7, Problem 14P

Interpretation Introduction

a)

Interpretation:

To explain the Hofmann elimination of the given amines.

Concept introduction:

The Hofmann elimination is an E2 reaction that converts an amine into an alkene and occurs with a non-zaitsev stereo chemistry to form the less highly substituted double bond. To predict the product, we look at the reactant and identify the position from which elimination might occur (the positions two carbons away from nitrogen) then carry out an elimination using the most accessible hydrogen. In the present instance, the hydrogens on C – 3 are far away from the quaternary ammonium ion N⁺ (CH₃). The C – 3 hydrogen are less hindered and more accessible to the base ^–OH.

Interpretation Introduction

b)

Interpretation:

To explain the Hofmann elimination of the given amines.

Concept introduction:

Just like alcohol, amines can be converted into alkenes by an elimination reaction.

But because an amide ion, ^-NH₂ is a poor leaving group, it must be converted into a better leaving group.

Interpretation Introduction

c)

Interpretation:

To explain the Hofmann elimination of the given amines.

Concept introduction:

The given amine has two symmetrical groups is CH₃CH₂CH₂ – attached to the carbon C-4- carrying the amine ^–NH₂ group.

Interpretation Introduction

d)

Interpretation:

To explain the Hofmann elimination of the given amines.

Concept introduction:

The Hofmann elimination is an E2 elimination that converts an amine to an alkene and occurs with non-Zaitsev regiochemistry to form the less highly substituted double bond alkene as the major product.