Question

why ketones do not show cannizaro reaction ?

Answer 1

Cannizzaro reaction involves a hydride ion shift from the carbonyl carbon that is attacked by the base to another carbonyl carbon (as depicted in the mechanism). The former molecule then reforms to a carboxylic acid and the latter that receives the hydrogen to a ketone. Since, there is no hydrogen attached to the carbonyl carbon in a ketone therefore it does not undergo cannizzaro reaction.