Reactivity of NaHSO3

NaHSO3 is a mild reducing agent and it reacts with carbonyl compounds to form corresponding sulfonate salt. The reactivity of NaHSO3 depends on the nature of the carbonyl compound.

Compounds that react with NaHSO3

- Aldehydes: Aldehydes readily react with NaHSO3 to form corresponding sulfonate salt.
- Ketones: Ketones also react with NaHSO3 but require heating and addition of catalytic amount of acid.
- α,β-unsaturated carbonyl compounds: These compounds react with NaHSO3 to form sulfonate salt and the reaction is known as the Nef Reaction.

Compounds that do not react with NaHSO3

- Compounds that lack α-hydrogens: Compounds that lack α-hydrogens such as benzaldehyde and aromatic ketones do not react with NaHSO3.
- Enolizable compounds: Enolizable compounds such as β-diketones and β-ketoesters do not react with NaHSO3.

Answer explanation

The given compound CH3COCH3 is a ketone and it can react with NaHSO3 to form corresponding sulfonate salt. Similarly, acetaldehyde (CH3CHO) is an aldehyde and it can also react with NaHSO3 to form corresponding sulfonate salt.

On the other hand, CH3CHO is an enolizable compound and it does not react with NaHSO3. Hence, option B (CH3COCH2CH3) is the correct answer.