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Indian Forest Service (Mains)

Chemistry optional

  • 2 papers
  • 200 marks each
  • 3 h per paper

Paper II covers organic chemistry and spectroscopy.

Indian Forest Service (Mains), Chemistry optional · 2021 · Paper II

Q5(h). Photoproducts of ketone excitation

Question

Identify possible products A–E in the two photolysis branches of 2-pentanone, and the major photoadduct F of benzophenone with isobutylene. [reaction scheme given in the paper]

Answer in brief

A consistent type-I assignment is A = CO, B = methane, C = propene, D = ethane and E = n-hexane; F is 3,3-dimethyl-2,2-diphenyloxetane.

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As written for the answer booklet: the diagram carries the working, the lines stay short. Read here only; it is not offered as a download.

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Topic notes: organic photochemistry and Norrish reactions, with every Civil Services, IFoS and Geo-Scientist PYQ →

CoversNorrish type INorrish type IIPaterno–Büchi reactionoxetane2-pentanone photolysis

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