Final answer:
The reaction of a nitrile with a Grignard reagent yields an intermediate imine anion that is hydrolyzed to form a ketone. The mechanism involves a nucleophilic attack and subsequent hydrolysis.
Step-by-step explanation:
The reaction of a nitrile with a Grignard reagent involves several steps. First, the Grignard reagent attacks the nitrile carbon, resulting in the formation of an intermediate imine anion. This imine anion is then hydrolyzed by the addition of water, forming a ketone. The mechanism is similar to the reduction of a nitrile to an amine, except that only one nucleophilic addition occurs and the nucleophile is a carbanion instead of a hydride ion.