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UPSC Combined Geo-Scientist

Chemist

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

Mains Paper III covers analytical and organic chemistry.

UPSC Combined Geo-Scientist, Mains · 2020 · Mains Paper III

Q8(b). Benzilic acid rearrangement of phenanthrenequinone

Question

Phenanthrene is oxidised by Na₂Cr₂O₇/H₂SO₄ to X, then treated with hydroxide in ether to give Y. Identify X and Y and explain the rearrangement.

Answer in brief

X is phenanthrene-9,10-dione. Y is 9-hydroxyfluorene-9-carboxylate; acid workup gives the corresponding carboxylic acid.

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CoversBenzilic acid rearrangement of phenanthrenequinoneRing contraction

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