Question

Ketones react with Grignard reagent to produce ____________.

Options

• None of these

• secondary alcohols

• tertiary alcohols

• primary alcohols

Answer 1

Ketones react with Grignard reagent to produce tertiary alcohols.

Explanation:

The Grignard Reaction is the addition of an organomagnesium halide (Grignard reagent) to a ketone or aldehyde, to form tertiary or secondary alcohol, respectively. The reaction with formaldehyde leads to a primary alcohol.

Grignard Reagents are also used in the following important reactions:
The addition of an excess of a Grignard reagent to an ester or lactone gives tertiary alcohol in which two alkyl groups are the same, and the addition of a Grignard reagent to a nitrile produces an unsymmetrical ketone via a metalloimine intermediate.

$$\mathrm{RCOR}{\phantom{A}}_1+\mathrm{R}{\phantom{A}}_2\mathrm{MgX}⟶\mathrm{RC}(\mathrm{OH})\mathrm{R}{\phantom{A}}_1\mathrm{R}{\phantom{A}}_2$$