反应详情

温度

-78 °C

A solution containing the product from Example 19A (20 g, 85.5 mmol) in dichloromethane (340 mL) was treated dropwise with DIBAL (86 mL, 1 M in dichloromethane) at −78° C., stirred at −78° C. for 2 hours, treated with DIBAL (43 mL, 1 M in dichloromethane), stirred at −78° C. for 1 hour, treated with methanol (20 mL) at −78° C., warmed to 25° C., treated with dichloromethane (250 mL), saturated aqueous sodium potassium tartrate (350 mL), and pH 7 buffer (300 mL), stirred vigorously with a mechanical stirrer for 16 hours, and filtered through celite®. The aqueous phase was washed with chloroform, and the combined organic phase was washed with brine and dried over MgSO4, filtered and concentrated. The residue was chromatographed on silica gel eluting 0-4% methanol/chloroform to give the title compound (11.61 g, 71% yield).

1. stirringstirred at −78° C. for 1 hour
2. temperaturewarmed to 25° C.
3. stirringstirred vigorously with a mechanical stirrer for 16 hours
4. filtrationfiltered through celite®
5. washThe aqueous phase was washed with chloroform
6. washthe combined organic phase was washed with brine
7. dry with materialdried over MgSO4
8. filtrationfiltered
9. concentrationconcentrated
10. customThe residue was chromatographed on silica gel eluting 0-4% methanol/chloroform