Q22 · CSIR-NET Chemistry, December 2012
Paper: CSIR-NET December 2012 · Subject: Organic Chemistry · Chapter: Reagents, Reaction Mechanisms & Named Reactions · Topic: Reduction Reagents · 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 reaction sequence is 
(a)
(b)
(c)
(d)
Answer
Under review — not yet confirmed.
Answer: C
Explanation
LiAlH₄ reduces the enone 1,2 from the face opposite the 5-methyl (OH cis to Me); Ac₂O gives the allylic acetate and Me₂CuLi displaces it S_N2′ anti to the leaving group, so the new methyl at C-3 is trans to the C-5 methyl (c).
Study loop for Reagents, Reaction Mechanisms & Named Reactions