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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 · 2023 · Paper II

Q2(c). Lewis-acid dehydration and rearrangement

Question

Complete the reaction of cyclohexyldimethylcarbinol with boron trifluoride etherate, giving a mechanism and plausible reasons for the product spread. [reaction scheme given in the paper]

Answer in brief

A carbocation network gives mainly substituted alkenes: isopropylidenecyclohexane, isopropenylcyclohexane and 1-isopropylcyclohexene; ring-expanded alkenes are also mechanistically accessible.

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Read the whole 2023 solution2023 question paper

Topic notes: elimination reactions (E1, E2, E1cB, Saytzeff and Hofmann, anti-periplanar, Chugaev, Cope), with every Civil Services, IFoS and Geo-Scientist PYQ →

CoversBF₃ etherate dehydrationcarbocation rearrangementhydride shiftring expansionWagner–Meerwein rearrangement

All parts of Question 2