Indian Forest Service (Mains)
Chemistry optional
- 2 papers
- 200 marks each
- 3 h per paper
Paper II covers organic chemistry and spectroscopy.
All years
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Paper II, organic chemistry and spectroscopy
Question paper, 2021
Indian Forest Service (Mains), Chemistry optional. 12 pages, as issued by UPSC.
Every question of 2021, one page each60 parts in 8 questions, with the question as text and the key points of its answer
Question 1 40 marks
- 1(a)Aromaticity classifications5 marks
- 1(b)Photochemical hydrogen migration in a diene5 marks
- 1(c)Isotope-labelled acetate pyrolysis5 marks
- 1(d)Kinetic enolate aldol sequence5 marks
- 1(e)Natural rubber and polyethylene5 marks
- 1(f)Phenol to a reduced aryl ether5 marks
- 1(g)Photochemical cleavage and alkene isomerization5 marks
- 1(h)Hyperfine lines of an isotopic radical5 marks
Question 2 40 marks
Question 3 40 marks
- 3(a)(i)Hydrogen exchange in cyclopropyl ketones5 marks
- 3(a)(ii)Strongly shielded internal methyl groups5 marks
- 3(b)(i)Carbon–carbon bond formation from a bromoester5 marks
- 3(b)(ii)Intramolecular aldol condensation5 marks
- 3(c)(i)ESR resonance field5 marks
- 3(c)(ii)Aromaticity of five-membered heterocycles5 marks
- 3(d)(i)Haworth synthesis of a methoxytetralone5 marks
- 3(d)(ii)Cyanide substitution on a nitroaryl halide5 marks
Question 4 40 marks
- 4(a)(i)Cyclopentadiene and methyl acrylate5 marks
- 4(a)(ii)Tetraphenylcyclopentadienone cycloaddition5 marks
- 4(b)Oxidation and oxidative cleavage5 marks
- 4(c)(i)Substitution versus elimination of a primary bromide5 marks
- 4(c)(ii)Alcohol to chloride with retention5 marks
- 4(d)(i)Regioselective hydration of allylbenzene5 marks
- 4(d)(ii)Nucleoside and nucleotide structures5 marks
- 4(e)Three rearrangement and condensation sequences5 marks
Question 5 40 marks
- 5(a)Condensation of diethyl succinate5 marks
- 5(b)DNA bases and pairing5 marks
- 5(c)Vinylcyclopropane rearrangement5 marks
- 5(d)Oxidation of 2-acetylpyridine5 marks
- 5(e)Azobenzene and hydrazobenzene5 marks
- 5(f)Nitration of indole5 marks
- 5(g)Acidity of cyclopentadiene derivatives5 marks
- 5(h)Photoproducts of ketone excitation5 marks
Question 6 40 marks
- 6(a)(i)Malonic ester ring synthesis5 marks
- 6(a)(ii)Wittig olefination5 marks
- 6(b)(i)Tertiary protein structure5 marks
- 6(b)(ii)End-group content of polystyrene5 marks
- 6(c)(i)Cyclization of a beta-hydroxy phenethylamide5 marks
- 6(c)(ii)Terylene from p-xylene5 marks
- 6(d)Fischer indole synthesis5 marks
- 6(e)Acid equivalent of nylon-6,65 marks
Question 7 40 marks
- 7(a)(i)A beta-chloroamine and sulfonyl chloride5 marks
- 7(a)(ii)Hydration followed by oxidation5 marks
- 7(b)Ireland–Claisen rearrangement of an allylic acetate10 marks
- 7(c)(i)Solvolysis of a tertiary allylic bromide5 marks
- 7(c)(ii)Ring expansion of vinylcyclobutane5 marks
- 7(d)Stability of triarylmethyl radicals5 marks
- 7(e)State-dependent diene chemistry and photo-Fries rearrangement5 marks
Question 8 40 marks
- 8(a)(i)Methylcyclohexenes by mass spectrometry5 marks
- 8(a)(ii)Hydroxy-methoxyacetophenone assignment5 marks
- 8(b)Identification of an aromatic diester10 marks
- 8(c)(i)Oxidative coupling of acetic anhydride5 marks
- 8(c)(ii)Cyclopentenone photocycloadditions5 marks
- 8(d)Photochemical cycloaddition and cleavage5 marks
- 8(e)IR distinctions between functional groups5 marks