Indian Forest Service (Mains), Chemistry optional · 2022 · Paper II
Q3(e). Stability of three carbanions
Question
Arrange R₃C–CH₂⁻, R₂C=CH⁻ and R–C≡C⁻ in order of stability, with justification.
Answer in brief
The conventional order is alkyl carbanion < vinylic carbanion < acetylide.
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Coverscarbanion stabilitys characteracetylide ionhybridizationC–H acidity
All parts of Question 3
- 3(a)(i) Amination of 2-chloropyridine5 marks
- 3(a)(ii) Amination through 3,4-pyridyne10 marks
- 3(b) Steric control of Diels–Alder reactivity5 marks
- 3(c) Cinnamaldoxime rearrangement and ring closure10 marks
- 3(d) Aromatic character of diazines5 marks
- 3(e) Stability of three carbanions5 marks