Q15 · 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
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 structures of A and B in the following reaction sequence are 
(a)
(b)
(c)
(d)
Answer
Under review — not yet confirmed.
Answer: D
Only (d) shows a chemically correct A; the second step as printed changes nothing.
Explanation
t-BuOK/MeI dimethylates the α-carbon; NaBH₄, acetylation and Et₃SiH/TFA ionic hydrogenolysis remove the benzylic oxygen, giving the gem-dimethyl tetralin methyl ether A (d); at −40 °C in THF the aryl methyl ether survives, so B = A (d).
Study loop for Reagents, Reaction Mechanisms & Named Reactions