Question:What starting materials are needed to synthesize each compound by a crossed Claisen reaction?

The Claisen reaction involves two different ester groups: one that can form an enolate and the other that cannot. The $\mathit{\alpha }$-hydrogen of one ester gets deprotonated and attacks at the electrophilic carbonyl carbon center of the other.

Retrosynthesis is the method employed to determine the synthetic pathway of a reaction and the starting materials participating in the reaction.

The analysis is done based on the product, and the breakdown is performed by keeping it as the target molecule.

a.

The retrosynthetic analysis of the given compound is as follows.

Retrosynthesis of compound a

b.

The retrosynthetic breakdown of the given compound is as follows.

Retrosynthesis of compound c

d.

The retrosynthetic breakdown of the given compound is as follows.

Retrosynthesis of compound d