Starting with methyl propanoate, how could you prepare 4-methyl-3-heptanone?

The Claisen condensation is the reaction between the two esters and the ester and the carbonyl compound to give $\mathbf{\beta }$keto ester and$\mathbf{\beta }$diketones.

The reaction is carried out in the presence of a strong base. This carbon-carbon bond forms a reaction.

Because the starting material is an ester and the target molecule has more carbons than the starting material, a Claisen condensation appears to be a good way to start this synthesis. The Claisen condensation forms a $\mathrm{\beta }$- keto ester that can be easily alkylated at the desired carbon because it is flanked by two carbonyl groups. Acid-catalyzed hydrolysis forms a 3-oxocarboxylic acid that decarboxylates when heated.

The mechanism of the reaction is as follows;

Mechanism of the reaction