Chapter 22.17, Problem 22.51P

(a)

Interpretation Introduction

Interpretation:

The validation of the fact that the given compound cannot be synthesized by acetoacetic ester synthesis is to be stated with an explanation.

Concept introduction:

The final products of acetoacetic ester synthesis are ketones, specially substituted derivatives of acetone. In acetoacetic ester synthesis, substituents are added to the enolate ion of acetoacetic ester. Then, hydrolysis takes place followed by decarboxylation to give alkylated derivatives of acetone.

(b)

Interpretation Introduction

Interpretation:

The compound shown in part (a) is to be synthesized from 1,3-diphenylacetone.

Concept introduction:

LDA (Lithium Di-isopropyl Amide) is a strong base with a molecular formula, ${\left[{\left({\text{CH}}_{\text{3}}\right)}_{\text{2}}\text{CH}\right]}_{\text{2}}\text{NLi}$. It is most commonly used in the formation of enolates. Enolate acts as a useful nucleophile that participates in ${\text{S}}_{\text{N}}\text{2}$ reaction as well as aldol reaction.

(c)

Interpretation Introduction

Interpretation:

The compound shown in part (b) is to be synthesized from 1,3-diphenylacetone using enamine reaction.

Concept introduction:

When a ketone reacts with a secondary amine, enamines are formed. The nitrogen analog of an enol is known as enamine. From the resonating structures of enamine, it is clear that it nucleophilic in nature.