Question

Ketones react with $Mg-Hg$ over water gives :

• A. pinacolone
• B. pinacols
• C. alcohols
• D. none of these

Answer 1

Answer: (B)

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.
$2^{\circ }$ alcohol (except formaldehyde which form $1^{\circ }$ alcohol).