Sodium borohydride → 11beta-fluoro-7alpha-{5-[(2S)-2-(4-trifluoromethylphenylthiomethyl)-pyrrolidin-1-yl]-pentyl}-estra-1,3,5(10)-triene-3,17beta-diol

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Reaction Steps

A solution of 0.43 g of 11β-fluoro-3-hydroxy-7α-{5-[(2S)-2-(4-trifluoromethylphenylthiomethyl)-pyrrolidin-1-yl]-pentyl}-estra-1,3,5(10)-trien-17-one in 4 ml of tetrahydrofuran, 2.3 ml of ethanol and 1 ml of water is mixed in portions at 0° C. with 111 mg of sodium borohydride, and it is stirred for 2 hours. Then, it is added to ice water, extracted three times with ethyl acetate, washed with common salt solution, dried on sodium sulfate, concentrated by evaporation in a vacuum and chromatographed on silica gel with dichloromethane/acetone. 0.32 g of 11β-fluoro-7α-{5-[(2S)-2-(4-trifluoromethylphenylthiomethyl)-pyrrolidin-1-yl]-pentyl}-estra-1,3,5(10)-triene-3,17β-diol with [α]D22 =+16.2° (c=0.51% in methanol) is obtained.

Provenance & Evidence