Q23 · CSIR NET Chemistry, June 2015
Paper: CSIR NET June 2015 · Subject: Organic Chemistry · Chapter: Reagents, Reaction Mechanisms & Named Reactions · Topic: Reagents, Reaction Mechanisms & Named Reactions – General · Marks: 2 · Difficulty: Easy
Structure of the major product in the following synthetic sequence is 
$\xrightarrow{\substack{1.\ \mathrm{CuI}\\ 2.\ \mathrm{SeO_2}}}$
$\xrightarrow{\substack{1.\ \mathrm{CuI}\\ 2.\ \mathrm{SeO_2}}}$(a)
(b)
(c)
(d)
Answer
Answer: A ✓ checked by 4AB · confidence medium
Explanation
Cu(I) forms a carbenoid from the diazo compound, which cyclopropanates the nearby internal alkene intramolecularly. SeO₂ then oxidises the terminal prenyl group at the E-methyl, giving the (E)-allylic alcohol (a).
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