Chapter 19, Problem 51P

Interpretation Introduction

Interpretation:

The base-catalyzed condensation reaction taking place between a malonic ester and 4-methyl-3-penten-2-one, leading to the formation of Dimedone, is to be shown.

Concept introduction:

When a compound containing an active methylene group is treated with a base, the proton is abstracted by the base and a carbon center nucleophile is generated. In the α,β-unsaturated carbonyl system, the β-position is electron deficient due to the conjugation of the carbon–carbon double bonds. The nucleophile attacks at the center and an aldol type condensation enables the ring closure.