反应详情

Compound (43) (3.40 g), 4.45 g of diphenylphosphorylazide, 1.9 of triethylamine, and 50 ml of t-butyl alcohol were mixed and the mixture was heated under reflux for 12 hours. The reaction mixture was concentrated under reduced pressure, and the residue was dissolved in chloroform. The solution was washed successively with a 10% citric acid aqueous solution, a 2% sodium hydroxide aqueous solution, and water and dried over anhydrous sodium sulfate. The solvent was evaporated, and the residue was purified by silica gel column chromatography using chloroform-methanol (97.5:2.5 by volume) as an eluent to obtain 1.76 g of (±)-cis-1-benzyl-4-t-butoxycarbonylamino-3-methyl-2-oxopyrrolidine (44) as a colorless oil.

1. temperaturethe mixture was heated
2. temperatureunder reflux for 12 hours
3. concentrationThe reaction mixture was concentrated under reduced pressure
4. dissolutionthe residue was dissolved in chloroform
5. washThe solution was washed successively with a 10% citric acid aqueous solution
6. dry with materiala 2% sodium hydroxide aqueous solution, and water and dried over anhydrous sodium sulfate
7. customThe solvent was evaporated
8. customthe residue was purified by silica gel column chromatography