Carbonyl compound forming chiral products with both HCN and NaBH4

Steps:

• HCN adds to C=O forming cyanohydrins; a chiral center forms if the carbonyl has two different substituents.
• NaBH4 reduces C=O to alcohols; a chiral center forms only in unsymmetrical ketones (R ≠ R').
• Both reactions must yield chiral products, so Q is an unsymmetrical ketone.
• Check options: butanone (CH₃COCH₂CH₃) has methyl and ethyl groups, fitting both criteria.

Why A is correct:

• Butanone is unsymmetrical; HCN gives CH₃(CH₃CH₂)C(OH)CN (chiral), NaBH₄ gives CH₃(CH₃CH₂)CHOH (chiral).

Why the others are wrong:

• B. Ethanol: Alcohol, not a carbonyl; no reaction with HCN or NaBH₄ to form chiral products.
• C. Propanal: HCN gives chiral cyanohydrin, but NaBH₄ gives achiral 1-propanol (primary alcohol).
• D. Propanone: Symmetrical ketone; both cyanohydrin and alcohol (isopropanol) lack a chiral center.

Final answer: A