question_answer

Ketones react with Mg - Hg over water gives :

A) pinacolone         

B) pinacols

C) alcohols               

D) none of these

Correct Answer: B

Solution :

Ketones on reduction with magnesium amalgum and water form pinacols Ketones upon reaction with Grignard regent from tertiary-alcohol. Formaldehyde with Grignard reagent forms primary alcohol, acetaldehyde with Grignard reagent forms secondary alcohol. \[{{\text{2}}^{\text{o}}}\]alcohol (except formaldehyde which form \[{{1}^{\text{o}}}\] alcohol).