[CH:1]([O:8][CH2:9][CH3:10])(OCC)OCC.C(O[C@@H:15]1[C@H:21]2[C@H:22]3[C@H:31]([CH2:32][CH2:33][C@:18]2([CH2:19][CH3:20])[C:17](=[O:35])[CH2:16]1)[C@@H:30]1[C:25](=[CH:26]C(=O)[CH2:28][CH2:29]1)[CH2:24][CH2:23]3)(=O)C.C(N(CC)CC)C.O>CCO.C1(C)C=CC(S(O)(=O)=O)=CC=1>[CH2:9]([O:8][C:1]1[CH2:28][CH2:29][C@H:30]2[C:25](=[CH:24][CH2:23][C@@H:22]3[C@@H:31]2[CH2:32][CH2:33][C@@:18]2([CH2:19][CH3:20])[C@H:21]3[CH:15]=[CH:16][C:17]2=[O:35])[CH:26]=1)[CH3:10]
Triethyl orthoformate (15 ml, 90.3 mmol) and p-Toluenesulfonic acid (250 mg, 1.31 mmol) were added to a suspension of 15α-acetoxy-18-methyl-estr-4-en-3,17-dione (25 g, 72.7 mmol) in EtOH (150 ml). The mixture was stirred at room temperature for 1 h. Triethylamine (25 ml, 179.4 mmol) was added. The mixture was heated under reflux for 2 h, cooled to 5° C. and water (75 ml) was then added. The precipitate was filtered, washed with a 1/1 EtOH/water solution and dried under vacuum to afford 3-ethoxy-18-methyl-estra-3,5,15-trien-17-one (20 g, yield: 88%).
読み込み中…
