反应详情

tert-Butyl [(1R)-1-{[(cyclohexylmethyl)amino]carbonyl}-3-(methylthio)propyl]carbamate (5.12 g) was dissolved in methyl iodide (23 mL) and stirred at room temperature for 18 hours. The excess methyl iodide was evaporated in vacuo. The residue was dissolved in tetrahydrofuran (50 mL), added lithium bis(trimethylsilyl)amide 1.0M solution in hexane (16.3 mL) at o 0° C., and then allowed to warm to room temperature and stirred for 5 hours. The resulting mixture was poured into aqueous ammonium chloride and extracted with ethyl acetate. The organic phase was washed with brine, dried over MgSO4, concentrated in vacuo. The residue was purified by silica gel column chromatography (hexane/ethyl acetate=from 80/20 (v/v) to 60/40 (v/v)) to give tert-butyl [(3R)-1-(cyclohexylmethyl)-2-oxo-3-pyrrolidinyl]carbamate (2.0 g) as a pale yellow solid.

1. customThe excess methyl iodide was evaporated in vacuo
2. dissolutionThe residue was dissolved in tetrahydrofuran (50 mL)
3. additionadded lithium bis(trimethylsilyl)amide 1.0M solution in hexane (16.3 mL) at o 0° C.
4. temperatureto warm to room temperature
5. stirringstirred for 5 hours
6. additionThe resulting mixture was poured into aqueous ammonium chloride
7. extractionextracted with ethyl acetate
8. washThe organic phase was washed with brine
9. dry with materialdried over MgSO4
10. concentrationconcentrated in vacuo
11. customThe residue was purified by silica gel column chromatography (hexane/ethyl acetate=from 80/20 (v/v) to 60/40 (v/v))