Q3(a)(i). Products of two reactions
Write the structure of the product formed in the following reactions: (1) 2-bromocyclohexanone with MeO⁻; (2) ethyl N-(p-nitrobenzenesulfonyloxy)carbamate with NEt₃ in the presence of cis-pent-2-ene (in excess). [structures given in the paper]
Answer in brief
(1) Methyl cyclopentanecarboxylate, by the Favorskii rearrangement (ring contraction); (2) ethyl cis-2-ethyl-3-methylaziridine-1-carboxylate, through a singlet nitrene.
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CoversFavorskii rearrangementcyclopropanonenitreneaziridinering contractionα-elimination
All parts of Question 3
- 3(a)(i) Products of two reactions10 marks
- 3(a)(ii) Ketone A from isobutanol alone5 marks
- 3(b)(i) Cyclopropane from tert-butyl chloroacetate and ethyl acrylate10 marks
- 3(b)(ii) Structures of C and D5 marks
- 3(c)(i) Missing reagents and intermediate10 marks
- 3(c)(ii) Photolysis of the α-diazoketone in methanol10 marks