Question

Total number of methyl group present in product $A$ is:

Answer 1

This is an example of organometallic chemical reaction called Grignard reaction. In this reaction, a Grignard reagent, which is an alkyl, aryl or vinyl-magnesium halide, reacts with an aldehyde, ketone or ester, resulting in formation of a carbon-carbon bond. The mechanism of this reaction can be explained as: First, the nucleophilic Grignard reagent attacks the electrophilic carbonyl carbon, and then acidic work up leads to protonation, resulting in formation of alcohol. This is explained in the mechanism.

In a molecule of ester, two molecules of Grignard reagent can be added. The resulting compound contains 4 methyl groups.