反应详情

Diisobutylaluminum hydride (1.0 M solution in dichloromethane, 99.0 ml, 99 mmol) was added dropwise to a stirred and cooled (−35° C.) solution of lovastatin (20.0 g, 49.4 mmol) in tetahydrofuran (200 ml) in a period of 1 hours. Stirring was continued for 1 hour at −35° C. Celite (20 g) and sodium sulphate decahydrate (30 g) were added. The mixture was stirred for 20 min. Cooling bath was removed and stirring was continued for 1 hour. The mixture was filtered through a pad of Celite (8.0×1.5 cm) and the solid was washed with ethyl acetate. Evaporation of the combined filtrate gave crude hemiacetals II (19.0 g, yield 99%) as a white foam (HPLC purity>96%). This was used without further purification in the next step.

1. stirringStirring
2. stirringThe mixture was stirred for 20 min
3. temperatureCooling bath
4. customwas removed
5. stirringstirring
6. waitwas continued for 1 hour
7. filtrationThe mixture was filtered through a pad of Celite (8.0×1.5 cm)
8. washthe solid was washed with ethyl acetate
9. customEvaporation of the combined filtrate