The major product in the following reaction sequence is (i) mCPBA, NaHCO₃ · ABC26OR0697
Subject: Organic Chemistry · Chapter: Reagents, Reaction Mechanisms & Named Reactions · Topic: Reagents, Reaction Mechanisms & Named Reactions – General · Exam: GATE 2000-2022 · Marks: 2 · Difficulty: Medium
The major product in the following reaction sequence is 
(i) mCPBA, $\mathrm{NaHCO_3}$ 
(i) mCPBA, $\mathrm{NaHCO_3}$ (a)
(b)
(c)
(d)
Answer
Answer (as printed): A
Explanation
(i) mCPBA (buffered with NaHCO₃) does a Baeyer–Villiger oxidation of the bicyclo[2.2.1]heptenone. The bridgehead carbon migrates, giving the bicyclic lactone. (ii) NaOH/H₂O hydrolyses the lactone to the cis-hydroxy carboxylate on a cyclopentene ring that carries the CH₂OMe side chain. (iii) I₂/KI/NaHCO₃ brings about iodolactonisation: the carboxylate attacks the iodonium ion anti to iodine. This closes a γ-lactone cis-fused to the cyclopentane, with I trans to the lactone oxygen, while the OH and CH₂OMe stay in place. The product is the Corey iodolactone, option (a).
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