Estrone → 17-Methylene-estra-1,3,5(10)-trien-3-ol

Participants

Reaction Steps

A suspension of methyltriphenylphosphonium bromide (100.03 g, 0.28001 mol) and potassium t-butoxide (31.42 g, 0.2800 mol) in anh. dimethylsulfoxide (DMSO, 320 mL) under argon was stirred in an oil bath (68°-81° C.) 1 h, after which estrone (15.14 g, 55.99 mmol) in anh. DMSO (320 mL) was added via syringe. See FIG. 17. Stirring was continued 1 h and the reaction allowed to cool. The mixture was poured into 800 mL of ice-1N hydrochloric acid and then extracted three times with 400 mL aliquots of ether. The combined organic extracts were washed with 350 mL of saturated sodium bicarbonate+400 mL of brine, dried over sodium sulfate, and flash filtered through a 58 mm high×84 mm dia. column of silica gel (200-40 mesh). Product continued eluting with additional ether. Concentration of appropriate fractions under reduced pressure and three-fold recrystallization from aqueous ethanol gave very fine white needles (11.47 g, 42.73 mmol, 76%), m.p. 134°-136° C., homogeneous to TLC (20% ethyl acetate/hexanes on silica gel, Rf 0.45). (NA-1994A-242B)

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