Q7(a)(i). Schmidt reaction of a cyclohexanone with an alkyl azide
Complete the following reactions and sketch a suitable mechanism for these reactions: 4-R¹-cyclohexanone + R²–N₃, TFA → ? [structure given in the paper]
Answer in brief
Product: the N-substituted caprolactam 1-R²-5-R¹-azepan-2-one + N₂; Schmidt reaction: the ring expands from six to seven atoms by insertion of N–R² next to C=O.
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CoversSchmidt reactionalkyl azidelactamring expansioncaprolactam1,2-shift
All parts of Question 7
- 7(a)(i) Schmidt reaction of a cyclohexanone with an alkyl azide5 marks
- 7(a)(ii) Robinson annulation of 2-methylcyclohexane-1,3-dione5 marks
- 7(b) Oxepin: 6π electrocyclic ring closure, then Diels–Alder addition5 marks
- 7(c) Chloromethylation, then Sommelet–Hauser rearrangement5 marks
- 7(d)(i) Iodolactonisation of a cyclopentenylacetic acid5 marks
- 7(d)(ii) Epoxidation, then acid-catalysed ring expansion to a ketone5 marks