Isobutyraldehyde on reaction with formaldehyde and K2CO3 gives compound 'A'. Compound 'A' reacts with KCN and yields compound 'B', which on hydrolysis gives a stable compound 'C'. The compound 'C' is :
(A)(see structure)
(B)(see structure)
(C)(see structure)✓ Correct
(D)(see structure)
Answer: (C)
Solution
Isobutyraldehyde undergoes aldol condensation with formaldehyde in the presence of base (K2CO3) to give compound A (a β-hydroxy aldehyde). Compound A reacts with KCN to form cyanohydrin B. Upon hydrolysis, the cyanohydrin converts to an α-hydroxy acid. The "stable" compound C indicates intramolecular cyclization occurs, forming a lactone (cyclic ester). The five-membered lactone shown in option (C) is the stable product formed from the α-hydroxy acid with two methyl groups.
JEE Main · 2022 · 28 Jun 2022 · Shift 2 · Single correct option
