Q21 · CSIR-NET Chemistry, December 2015
Paper: CSIR-NET December 2015 · Subject: Organic Chemistry · Chapter: Reagents, Reaction Mechanisms & Named Reactions · Topic: Reagents, Reaction Mechanisms & Named Reactions – General · Marks: 2 · Difficulty: Medium
The major product formed in the following reaction sequence is: 
(a)
(b)
(c)
(d)
Answer
Answer: D ✓ checked by 4AB · confidence high
Explanation
LiCH(OMe)SPh adds to boron and HgCl₂ induces 1,2-migration of the cyclopentyl group with loss of PhS⁻ (one-carbon homologation); H₂O₂/NaOH oxidises the α-methoxy boronate to the aldehyde with retention (d).
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