Oxygenation of 2,4-dibromoestrogens with nitric acid: A new synthesis of 19-nor steroids.
作者:Mitsuteru NUMAZAWA、Kumiko HOSHI、Katsuhiko KIMURA
DOI:10.1248/cpb.37.2058
日期:——
A convenient synthesis of 19-nor steroids 4a, 4b, 12a, and 12c is described. Oxygenation of 2, 4-dibromoestrogens 1a, 1b, 8a, and 8b with nitric acid in acetic acid gave the corresponding 2, 4-dibromo-10β-hydroxy-1, 4-dien-3-one derivatives 2a, 2c, 9a, and 9d in excellent yields. These 10β-hydroxy-dienones were subjected to catalytic hydrogenation over palladium-on-charcoal to afford the saturated 5ξ-3-oxo derivatives 3a, 3b, 10a, and 10b, respectively, in very high yields. These saturated products were then converted into the corresponding 19-nor steroids 4a, 4b, 12a, and 12c by treatment with acid, perchloric acid, p-toluenesulfonic acid or Nafion-H.
本文介绍了一种简便的 19-去甲类固醇 4a、4b、12a 和 12c 的合成方法。将 2,4-二溴雌激素 1a、1b、8a 和 8b 在乙酸中用硝酸氧合,可得到相应的 2,4-二溴-10β-羟基-1,4-二烯-3-酮衍生物 2a、2c、9a 和 9d,收率极高。将这些 10β- 羟基二烯酮在炭化钯上进行催化氢化,可分别得到饱和的 5ξ-3-氧代衍生物 3a、3b、10a 和 10b,收率非常高。然后,这些饱和产物通过酸、高氯酸、对甲苯磺酸或 Nafion-H 处理,转化为相应的 19-去甲类固醇 4a、4b、12a 和 12c。