Q15 · CSIR-NET Chemistry, June 2018
Paper: CSIR-NET June 2018 · Subject: Organic Chemistry · Chapter: Reagents, Reaction Mechanisms & Named Reactions · Topic: Named Reactions · Marks: 2 · Difficulty: Medium
Under review — part of this question (a structure or an option) is not clear in the source scan. 4AB is checking it against the original book; the answer shown may change.
The major product formed in the following oxidation reaction is 
iii) $\mathrm{Br_{2}}$, $\mathrm{CCl_{4}}$
iii) $\mathrm{Br_{2}}$, $\mathrm{CCl_{4}}$(a)
(b)
(c)
(d)
Answer
Under review — not yet confirmed.
Answer: D
The source book printed B; on checking, D is correct — see the explanation.
Explanation
Urea–H₂O₂ mono-epoxidises 1,5-cyclooctadiene and aqueous acid opens the epoxide to the trans-diol; Br₂ then forms a bromonium on the remaining alkene, which the transannular hydroxyl opens to the 9-oxabicyclo[3.3.1] ether with Br anti to the new C–O bond and the other OH untouched (d).
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