Q69 · CSIR NET Chemistry, June 2013
Paper: CSIR NET June 2013 · Subject: Organic Chemistry · Chapter: Photochemical Reactions · Topic: Photocycloaddition · Marks: 2 · Difficulty: Medium
The following photochemical conversion proceeds through 
(a)Barton reaction
(b)Paterno-Büchi reaction
(c)Norrish type I reaction
(d)Norrish type II reaction
Answer
Answer: D ✓ checked by 4AB · confidence medium
Explanation
The excited ketone abstracts a γ-H and β-cleavage opens the second ring. This gives the cyclohexanone carrying an alkenyl chain: Norrish type II (d).
Study loop for Photochemical Reactions