Q7 · CSIR-NET Chemistry, December 2011
Paper: CSIR-NET December 2011 · Subject: Organic Chemistry · Chapter: Reagents, Reaction Mechanisms & Named Reactions · Topic: Reagents, Reaction Mechanisms & Named Reactions – General · 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 products A and B in the following reaction sequence are 
(a)
(b)
(c)
(d)
Answer
Under review — not yet confirmed.
Answer: A
Explanation
NBS/ethyl vinyl ether converts the allylic alcohol into the bromoacetal A; Bu₃SnH/AIBN generates the primary radical, which cyclises 5-exo onto the ring alkene to give the saturated cis-fused bicyclic acetal B (a).
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