反应详情

温度

-35 °C

215 mg of 2-methoxy-estra-1,3,5(10)-triene-3,17β-diol was dissolved in 20 ml of absolute dichloromethane and cooled to −35° C. Then, 280 μl of diethylamino sulfur trifluoride was added, and the cold bath was removed. After 1 hour, it was poured into aqueous sodium bicarbonate solution and extracted with dichloromethane (3×). The combined organic phases were dried and concentrated by evaporation in a rotary evaporator. Flash chromatography (cyclohexane/ethyl acetate=10:1) yielded 49% crude product, which was purified by means of HPLC (Chiracel OD-H 250×4.6 mm; n-heptane/2-propanol=95/5). 46 mg (21%) of 17α-fluoro-3-hydroxy-2-methoxy-estra-1,3,5(10)-triene was obtained as colorless crystals.

1. customthe cold bath was removed
2. additionit was poured into aqueous sodium bicarbonate solution
3. extractionextracted with dichloromethane (3×)
4. customThe combined organic phases were dried
5. concentrationconcentrated by evaporation in a rotary evaporator
6. customFlash chromatography (cyclohexane/ethyl acetate=10:1) yielded 49% crude product, which
7. customwas purified by means of HPLC (Chiracel OD-H 250×4.6 mm; n-heptane/2-propanol=95/5)