UPSC Civil Services (Mains), Chemistry optional · 2025 · Paper II
Q6(c)(iv). A, B and C from the mixed ketones
Question
Assign A, B and C in the following reaction: Ph₂CH–CO–CHPh₂ + PhCH₂–CO–CH₂Ph (hν) → A + B + C (major) + CO.
Answer in brief
C (major) = 1,1,2-triphenylethane, Ph₂CH–CH₂Ph; A and B = Ph₂CH–CHPh₂ and PhCH₂–CH₂Ph.
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CoversNorrish type Iα-cleavagedecarbonylationcrossover experimentbenzylic radical
All parts of Question 6
- 6(a)(i) Products and intermediates of two reductions10 marks
- 6(a)(ii) Role of NMO in catalytic dihydroxylation5 marks
- 6(b) Three numericals15 marks
- 6(c)(i) Benzene to fulvene by light5 marks
- 6(c)(ii) Quantum yield of photobromination5 marks
- 6(c)(iii) Photolysis of 4,5-dimethylhexan-2-one5 marks
- 6(c)(iv) A, B and C from the mixed ketones5 marks