Chapter 21, Problem 65PP

(a)

Interpretation Introduction

Interpretation:

Diethyl malonate reacts with bromine in acid catalyzed condition and the acidity of the product, structure of the product should be identified.

Concept introduction:

Under acid catalyzed conditions the carbonyl group gets protonated and gives a resonance stabilized intermediate resulting in formation of enol by deprotonation.  The enol acts as a nucleophile and undergoes bromination to give an $\alpha$-bromoketone or $\alpha$-bromoaldehyde (acid-catalyzed halogenation) which then deprotonation in presence of water acting as base to form the final product. Inductive effect of the substituted halide stabilizes the formed conjugate base which inturn makes the compound more acidic.

To Find: To find the product formed when diethyl malonate undergoes bromination in acid catalyzed condition

(b)

Interpretation Introduction

Interpretation:

Diethyl malonate reacts with bromine in acid catalyzed condition and the acidity of the product, structure of the product should be identified.

Concept introduction:

Under acid catalyzed conditions the carbonyl group gets protonated and gives a resonance stabilized intermediate resulting in formation of enol by deprotonation.  The enol acts as a nucleophile and undergoes bromination to give an $\alpha$-bromoketone or $\alpha$-bromoaldehyde (acid-catalyzed halogenation) which then deprotonation in presence of water acting as base to form the final product. Inductive effect of the substituted halide stabilizes the formed conjugate base which inturn makes the compound more acidic.

To propose : To propose the mechanism for the above reaction

(c)

Interpretation Introduction

Interpretation:

Diethyl malonate reacts with bromine in acid catalyzed condition and the acidity of the product, structure of the product should be identified.

Concept introduction:

Under acid catalyzed conditions the carbonyl group gets protonated and gives a resonance stabilized intermediate resulting in formation of enol by deprotonation.  The enol acts as a nucleophile and undergoes bromination to give an $\alpha$-bromoketone or $\alpha$-bromoaldehyde (acid-catalyzed halogenation) which then deprotonation in presence of water acting as base to form the final product. Inductive effect of the substituted halide stabilizes the formed conjugate base which inturn makes the compound more acidic.

To Predict: Whether product will be more acidic than starting material or not