Water → 21-Methylene-20(R)-methylpregn-4-en-3beta-ol

Participants

Reaction Steps

A suspension of 21-methylene-20(R)-methylpregn-4-en-3-one (5, 100.0 mg, 0.3063 mmol) and lithium tri-t-butoxyaluminohydride (319.4 mg, 1.256 mmol) in 5 mL of anh. THF was stirred under argon for 6 h, after which water (48 μL), 15% (w/w) sodium hydroxide (48 μL), and water (143 μL) were added. The mixture was filtered through diatomaceous earth and the residue was extracted four times with 5 mL aliquots of THF. Concentration of the combined filtrates under reduced pressure and two-fold recrystallization from aqueous ethanol gave white platelets (42.6 mg, 0.130 mmol, 42%), m.p. 121-123° C. TLC (25% ethyl acetate/hexanes on silica gel) shows major product at Rf 0.38 and minor product at Rf 0.43 (starting material Rf 0.50).

Provenance & Evidence