Q59 · CSIR-NET Chemistry, June 2012
Paper: CSIR-NET June 2012 · Subject: Organic Chemistry · Chapter: Photochemical Reactions · Topic: Photocycloaddition · Marks: 2 · Difficulty: Medium
Structure of the starting material A in the following photochemical Norrish reaction, is 
(a)
(b)
(c)
(d)
Answer
Answer: C ✓ checked by 4AB · confidence medium
Explanation
The product is a cyclopropyl ketone, which comes from the oxa-di-π-methane rearrangement of a β,γ-unsaturated ketone. The octalone (c), with the C=C at the ring fusion β,γ to the C=O, is the required substrate.
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