Water → 1,3-Dimethoxy-17beta-hydroxyestra-1,3,5(10)-triene

A solution of 1,3-dimethoxyestra-1,3,5(10)-trien-17-one (2.0 g, 6.4 mM) in 10 ml of anhydrous tetrahydrofuran is added dropwise to a well-stirred suspension of lithium tri-t-butoxyaluminum hydride (4.86 g, 19 mM) in 40 ml of anhydrous tetrahydrofuran at 0°. The suspension is maintained at 0° for 1 hr, warmed to 40° for 1/2 hr, cooled to room temperature and poured into 200 ml of cold H2O. The basic aqueous solution is extracted with 3 × 50 ml of ether and 3 × 50 ml of methylene chloride. The combined organic extracts are washed with H2O, dried over Na2SO4 and evaporated in vacuo to give an oily residue which is chromatographed on 100 g of neutral silica gel. Elution with chloroform gives 1,3-dimethoxy-17β-hydroxyestra-1,3,5(10)-triene, yield 1.9 g (95%); m.p. 53°-55° (hexane).