[CH:1]#[C:2][CH3:3].[CH2:4]([Li])[CH2:5][CH2:6]C.C([O:12][C@@H:13]1[C@H:18]2[C@H:19]3[C@H:29]([CH2:30][CH2:31][C@:16]2([CH3:17])[C:15](=O)[CH2:14]1)[C@:27]1([CH3:28])[C:22]([CH:23]=C(OC)CC1)=[CH:21][CH2:20]3)(=O)C.[Cl-].[NH4+].[O:37]1CCCC1>C(OCC)(=O)C>[OH:37][C@@:19]1([C:4]#[C:5][CH3:6])[CH:20]=[CH:21][C@H:22]2[C@H:23]3[C@H:31]([CH2:30][CH2:29][C@:27]12[CH3:28])[C@:16]1([CH3:17])[C:3](=[CH:18][C:13](=[O:12])[CH2:14][CH2:15]1)[CH2:2][CH2:1]3At 0° C., propyne is introduced for 30 minutes into 150 ml of butyllithium solution (1.6 molar in hexane) in 400 ml of tetrahydrofuran. Then 15 g of 15α-acetoxy-3-methoxyandrosta-3,5-dien-17-one in 300 ml of tetrahydrofuran is added dropwise thereto, the mixture is allowed to react for 1 hour and combined with saturated ammonium chloride solution. The mixture is diluted with ethyl acetate, washed with water, dried, and concentrated under vacuum. The crude product is combined dropwise with 10 ml of concentrated hydrochloric acid in a mixture of 300 ml of methanol and 20 ml of water at room temperature. After 1 hour, the reaction mixture is introduced into ice/water, the precipitated product is suctioned off, washed with water, dissolved in ethyl acetate, dried, and concentrated under vacuum. After chromatography of the crude product on silica gel with a hexane-ethyl acetate gradient, 6.3 g of 17β-hydroxy-17α-propyn-1-ylandrosta-4,15-dien-3-one is obtained as a foam.
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