[CH3:1][CH2:2][C@:3]12[CH2:19][CH2:18][C@H:17]3[C@@H:8]([CH2:9][CH2:10][C:11]4[C@@H:16]3[CH2:15][CH2:14][C:13](=[O:20])[CH:12]=4)[C@@H:7]1[CH:6]=[CH:5][C:4]2=[O:21].[C:22]1(C)C=CC(S(O)(=O)=O)=CC=1.N1C=CC=CC=1>O1CCOCC1.C(OC)(OC)OC>[CH3:22][O:20][C:13]1[CH2:14][CH2:15][C@H:16]2[C:11](=[CH:10][CH2:9][C@@H:8]3[C@@H:17]2[CH2:18][CH2:19][C@@:3]2([CH2:2][CH3:1])[C@H:7]3[CH:6]=[CH:5][C:4]2=[O:21])[CH:12]=1Under argon, 20.0 g of 18-methyl-4,15-estradiene-3,17-dione in 100 ml of 1,4-dioxane and 100 ml of trimethyl orthoformate is agitated with 800 mg of p-toluenesulfonic acid at 50° C. After 2.5 hours, 10 ml of pyridine is added and the solution extensively distilled under vacuum. The residue is dissolved in ethyl acetate, washed with water, and dried. Chromatography of the crude product with 0-20% ethyl acetate-hexane yields 14.0 g of 3-methoxy-18-methyl-3,5,15-estratrien-17-one, melting point 162.1° C. (from methanol).
読み込み中…
