[CH3:1][O:2][C:3]1[CH:20]=[CH:19][C:18]2[C@@H:17]3[C@H:8]([C@H:9]4[C@@:13]([CH2:15][CH2:16]3)([CH3:14])[C:12](=[CH2:21])[CH2:11][CH2:10]4)[CH2:7][CH2:6][C:5]=2[CH:4]=1.C(O)(C)(C)C.[Li].N>C1COCC1.O.CO>[CH3:1][O:2][C:3]1[CH2:4][C:5]2[CH2:6][CH2:7][C@@H:8]3[C@@H:17]([C:18]=2[CH2:19][CH:20]=1)[CH2:16][CH2:15][C@@:13]1([CH3:14])[C@H:9]3[CH2:10][CH2:11][C:12]1=[CH2:21]Approximately 70 mL of anh. ammonia was distilled through a KOH tower into a 250 mL flame-dried 3-neck flask fitted with an inlet adapter, magnetic stirring bar, dry ice/acetone condenser, and ground glass stopper. See FIG. 17. A solution of 17-methylenestra-1,3,5(10)-trien-3-yl methyl ether (14, 1.1297 g, 4.0001 mmol) and t-butyl alcohol (13.21 g, 0.1782 mol) in dry THF (17 mL) was added, followed by lithium wire (0.47 g, 68 mg-atom) cut in small pieces. After refluxing under argon for 6 h anh. methanol (6.6 mL) was added and the suspension was stirred overnight while allowing ammonia to boil off. Water (100 mL) was added and the suspension was extracted three times with 50 mL portions of methylene chloride. The combined organic extracts were washed with 100 mL of brine, dried over sodium sulfate, and filtered. The residue was washed with 25 mL of methylene chloride and the combined filtrates were concentrated under reduced pressure. The resulting light yellow oil was crystallized from aqueous ethanol to give lustrous white crystals (815.0 mg, 2.865 mmol, 72%), m.p. 77-78° C., homogeneous to TLC (Rf 0.60, 10% ethyl acetate/hexanes on silica gel). (NA-1994A-257)
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