Q107 · CSIR NET Chemistry, December 2019
Paper: CSIR NET December 2019 · Subject: Organic Chemistry · Chapter: Photochemical Reactions · Topic: Photocycloaddition · Marks: 2 · Difficulty: Medium
The major product formed in the following reaction is 
$h
u$
$h
u$(a)
(b)
(c)
(d)
Answer
Answer: D ✓ checked by 4AB · confidence medium
Explanation
Norrish type II: the excited carbonyl abstracts the γ-H of the propyl chain, giving a 1,4-biradical. Yang cyclisation closes it to the methyl-cyclobutanol fused to the cyclohexene (d).
Study loop for Photochemical Reactions