UPSC Combined Geo-Scientist, Mains · 2025 · Mains Paper III
Q9(a)(i). Dieckmann condensation, then NaBH₄ reduction
Question
Complete the following reaction and sketch a suitable mechanism for conversion of A → B. [diester A given in the paper; NaOEt → B; NaBH₄ → C]
Answer in brief
B = ethyl 2-oxoindane-1-carboxylate (cyclic β-keto ester). C = ethyl 2-hydroxyindane-1-carboxylate.
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CoversDieckmann condensationintramolecular Claisenbeta-keto esterNaBH4 reductionchemoselective reduction
All parts of Question 9
- 9(a)(i) Dieckmann condensation, then NaBH₄ reduction5 marks
- 9(a)(ii) Polyurethane: characteristic use and repeating unit5 marks
- 9(b)(i) HBr and buta-1,3-diene: kinetic and thermodynamic control5 marks
- 9(b)(ii) Sharpless asymmetric epoxidation of an allylic alcohol5 marks
- 9(c) Structure from IR, NMR and mass spectra: C₁₀H₁₃NO₂10 marks