To a suspension of 3-benzyloxy-2-nitroestra-1,3,5(10)-trien-17-one (79, 1.82 g, 4.5 mmol) in acetone (250 mL) were added 0.5 N aqueous NaOH (60 mL, 30 mmol) and sodium hydrosulfite (85%, 6.0 g) at 80° C., and stirred for 1 h. After the reaction mixture was cooled to room temperature, H2O (150 mL) was added, acetone was removed at reduced pressure, and the remainder allowed to stand for 3 h at 0° C. The precipitate was collected by filtration and washed with H2O to afford 1.15 g of 80 (68% yield) mp: 205-207° C.
