Malonic Ester Synthesis

Malonic ester is a reagent specifically used in a reaction which converts alkyl halides to carboxylic acids called the Malonic Ester Synthesis. Malonic ester synthesis is a synthetic procedure used to convert a compound that has the general structural formula 1 into a carboxylic acid that has the general structural formula 2.

Due to the fact that Malonic ester’s α hydrogens are adjacent to two carbonyls, they can be deprotonated by sodium ethoxide (NaOEt) to form Sodio Malonic Ester.

Because Sodio Malonic Ester is an enolate, it can then be alkylated with alkyl halides.

After alkylation the product can be converted to a dicarboxylic acid through saponification and subsequently one of the carboxylic acids can be removed through a decarboxylation step.

Mechanism

1) Saponification

2) Decarboxylation

3) Tautomerization

All of the steps together form the Malonic ester synthesis.

Example