Propose a mechanism for the self-condensation of methyl

Solution:

Here we have to propose a mechanism for the self-condensation of methyl 3-phenylpropionate catalyzed by sodium methoxide.

Step 1

Two molecules of  methyl 3-phenylpropionate on self condensation with sodium methoxide form 1-methoxy-2-methylphenyl-5-phenylpentan-1,3-dione.

2+ NaOCH3 

(Methyl-3-phenylpropionate)                        (sodium methoxide)           (1-methoxy-2-methylphenyl-5-phenylpentan-1,3-dione)

Mechanism:-