反应详情

温度

0 °C

N-Propanol (20 ml), benzylcarbamate (4 g, 27 mmol), and 1 ,3-dichloro-5,5-dimethylhydantoin (2.6 g, 13 mmol) are added to a solution of NaOH (1 g, 27 mmol) in water (40 ml). The reaction mixture is cooled to 0° C. and a solution of 2,5-dihydro-pyrrole-1 -carboxylic acid tert-butyl ester (1.51 g, 8.92 mmol) in n-propanol (10 ml) is added. A solution of potassium osmate (0.098 g, 0.268 mmol) in 0.65 M NaOH (1 ml) is added. The reaction mixture is stirred at 0° C. for 1 hour and then at room temperature for 2 hours. The reaction mixture is quenched with sodium sulfite (1.90 g, 15 mmol) and diluted with approximately 1:1 EtOAc:water (100 ml). The aqueous layer is extracted with ethyl acetate, the combined organic extracts dried (MgSO4) and concentrated. Purification on a silica gel column (4:1 hexanes:EtOAc) yields 3-benzyloxycarbonylamino-4-hydroxy-pyrrolidine-1-carboxylic acid tert-butyl ester.

1. waitat room temperature for 2 hours
2. extractionThe aqueous layer is extracted with ethyl acetate
3. dry with materialthe combined organic extracts dried (MgSO4)
4. concentrationconcentrated
5. customPurification on a silica gel column (4:1 hexanes:EtOAc)