Question

The product obtained on the reaction of propanone with \( CH_3MgBr \) followed by hydrolysis is

• A. 2-Methylpropan-2-ol
• B. Butan-1-ol
• C. Butan-2-ol
• D. 2-Methylpropan-1-ol
• E. 2-Methylpropane

Hint:

In Grignard reactions with ketones, the addition of the Grignard reagent forms a secondary alcohol after hydrolysis, and the structure of the final alcohol depends on the ketone and the reagent used.

Answer 1

The Correct Option is D

The reaction involves propanone (CH₃COCH₃) reacting with methylmagnesium bromide (CH₃MgBr), which is a Grignard reagent. When a Grignard reagent reacts with a ketone, it adds to the carbonyl group and the subsequent hydrolysis yields an alcohol. - Propanone is a ketone (CH₃COCH₃). When it reacts with CH₃MgBr, the nucleophilic methyl group (from CH₃MgBr) adds to the carbonyl carbon of propanone, producing an intermediate that, after hydrolysis, gives 2-Methylpropan-1-ol. This is a secondary alcohol (since the carbon attached to the -OH group is bonded to two other carbons). - Option (A): 2-Methylpropan-2-ol is incorrect, as the reaction with CH₃MgBr does not lead to the formation of this alcohol. - Option (B): Butan-1-ol is incorrect because this would be the product if the reaction were with ethanol or acetaldehyde, not propanone. - Option (C): Butan-2-ol is also incorrect because this is the product if the reaction were with butanone, not propanone. - Option (D): 2-Methylpropan-1-ol is the correct product of the reaction as described above. - Option (E): 2-Methylpropane is a hydrocarbon and would not be the product of this reaction. Thus, the correct answer is (D) 2-Methylpropan-1-ol.