Question

A carbonyl compound gives a positive iodoform test but does not reduce Tollen's reagent or Fehling's solution. It forms a cyanohydrin with $HCN$, which on hydrolysis gives a hydroxy acid with a methyl side chain. The compound is:

• A. acetaldehyde
• B. propionaldehyde
• C. acetone
• D. crotonaldehyde

Answer 1

Answer: (C)

acetone

Acetone gives a positive iodoform test as it is a methyl ketone. It does not reduce Tollen's reagent or Fehling's solution which are the test's characteristics of aldehydes.

Acetone forms a cyanohydrin with $HCN$ (characteristic of a carbonyl group) which on hydrolysis gives a hydroxy acid with a methyl side chain.