Concept:The addition of HCN to asymmetric ketones yields cyanohydrins with four different groups attached to the central carbon, creating a chiral center.
Solution:- Pentan-2-one has the structure \( CH_3-CO-CH_2CH_2CH_3 \). The carbonyl carbon is bonded to a methyl group and a propyl group.
- When \( HCN \) is added via nucleophilic addition, the carbonyl oxygen becomes an \( -OH \) group, and a \( -CN \) group attaches to the carbon.
- The resulting central carbon is now bonded to four distinct groups: Methyl (\( -CH_3 \)), Propyl (\( -C_3H_7 \)), Hydroxyl (\( -OH \)), and Cyano (\( -CN \)).
- A carbon atom bonded to four different groups is chiral. Thus, it gives a chiral product.
Why other options are incorrect:Option A is false; the reaction is base-catalyzed (requires free \( CN^- \)). Option C is false; it is an addition reaction, not condensation (no water is lost). Option D is false; it is an addition, not substitution.
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