Q108 · CSIR-NET Chemistry, December 2019

Paper: CSIR-NET December 2019 · Subject: Organic Chemistry · Chapter: Photochemical Reactions · Topic: Photocycloaddition · Marks: 2 · Difficulty: Medium

The major products A and B formed in the following reactions are Question structure 1 of 4, ABC26OR1086 Question structure 2 of 4, ABC26OR1086 A Question structure 3 of 4, ABC26OR1086 Question structure 4 of 4, ABC26OR1086
(a)A = Option (a) structure 1 of 2, ABC26OR1086 B = Option (a) structure 2 of 2, ABC26OR1086
(b)A = Option (b) structure 1 of 2, ABC26OR1086 B = Option (b) structure 2 of 2, ABC26OR1086
(c)A = Option (c) structure 1 of 4, ABC26OR1086 Option (c) structure 2 of 4, ABC26OR1086 B = Option (c) structure 3 of 4, ABC26OR1086 Option (c) structure 4 of 4, ABC26OR1086
(d)A = Option (d) structure 1 of 2, ABC26OR1086 B = Option (d) structure 2 of 2, ABC26OR1086
Answer
Answer: C ✓ checked by 4AB · confidence low
Explanation
I₂/O₂ stilbene photocyclisation gives the phenanthrene lactam A, and BCl₃ selectively cleaves the methoxy group next to the lactam C=O, assisted by chelation. Option (c) is not legible on the source page; the printed key gives (c).

Study loop for Photochemical Reactions

1. Practise the PYQsPrevious-year questions, with answers

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