Preparation of Alcohols Using Grignard Reagent

A Grignard reagent (R-MgX) adds as a nucleophile to the electrophilic carbonyl carbon of an aldehyde or ketone in dry ether; acid hydrolysis of the resulting magnesium alkoxide then liberates the alcohol. Formaldehyde (HCHO) gives a PRIMARY alcohol (e.g. phenylmagnesium bromide + HCHO, then H2O/H+, gives phenylmethanol/benzyl alcohol); other aldehydes give SECONDARY alcohols (e.g. ethylmagnesium bromide + acetaldehyde gives butan-2-ol); and ketones give TERTIARY alcohols (e.g. n-butylmagnesium bromide + acetone gives 2-methylhexan-2-ol). A formate ester (H-COO-R) reacting with TWO equivalents of a Grignard reagent gives a secondary alcohol beari …