91Ó°ÊÓ

The reaction of an aldehyde or a ketone with a Grignard reagent is a nucleophilic addition reaction—the nucleophilic Grignard reagent adds to the carbonyl carbon then it forms an alkoxide ion that is complexed with the magnesium ion. In the end addition of dilute acid breaks up the complex and we get the desired alcoholic product.

In the given reaction, first reagent used is Grignard reagent in the presence of acid HCl, which undergoes reaction with propanal to form an secondary alcohol, that goes on oxidation with second reagent NaOCl in the presence of acetic acid to form butan-2-one. This butan-2-one undergoes esterification by reagents HCl in the presence of excess alcohol to form an ester as a desired product as shown in the figure given below:

Selection of reagents