The first step of the reaction is the nucleophilic addition of Grignard
reagent to the carbonyl group to form an adduct Hydrolysis of the
adduct yields an alcohol (i) (ii)
The overall reactions using different aldehydes and ketones are as
follows:
You will notice that the reaction produces a primary alcohol with
methanal, a secondary alcohol with other aldehydes and tertiary alcohol
with ketones