反应详情

温度

12 °C

In a 250 ml three necked flask fitted with a magnetic stirrer and reflux condenser, under inert atmosphere, a solution of 8.48 g (32 mmol, 1 eq) of 1-(4-methoxy-benzyl)-5-oxo-pyrrolidine-3-carboxylic acid methyl ester al in 120 ml of EtOH is cooled down to 0° C. Solid NaBH4 (3.6 g, 96 mol, 3 eq) is then added by portions over 1.5 h, all the while maintaining the temperature between 2 and 4° C. After 2 h, the temperature is raised to 12° C. for 1 h, and lowered again to 2–4° C. A saturated solution of NH4Cl (240 ml) is added dropwise over 1 h, followed by 120 ml of acetone, and the mixture is left overnight at room temperature. The mixture is extracted by CH2Cl2 (3 times), dried on MgSO4, filtered and concentrated in vacuo to afford the crude alcohol which is purified by chromatography on silicagel (CH2Cl2/MeOH: 95/05 (v/v)) to give the pure alcohol a2 (4.3 g, 57%).

1. temperaturereflux condenser
2. temperatureall the while maintaining the temperature between 2 and 4° C
3. customlowered again to 2–4° C
4. waitthe mixture is left overnight at room temperature
5. extractionThe mixture is extracted by CH2Cl2 (3 times)
6. customdried on MgSO4
7. filtrationfiltered
8. concentrationconcentrated in vacuo
9. customto afford the crude alcohol which
10. customis purified by chromatography on silicagel (CH2Cl2/MeOH: 95/05 (v/v))