Functionalized enamines XXVIII. A facile synthesis of 6-methyl-19-norsteroids
作者:H. Bieräugel、U. K. Pandit
DOI:10.1002/recl.19790980906
日期:——
yields in the cyclization step are achieved by initial reduction of the 5-ring ketone function and acetylation of the resulting alcohol. The latter sequence of reactions with 14a, derived from 12, gives optically active 17β-acetoxy-6-methylestra-1,3,5,7,9,14-haxaen-3-ol methyl ether (15b), which can serve as an central intermediate for optically active steroids.
衍生自8a-甲基-1,6-二氧代-1,2,3,4,6,7,8,8,8a-八氢萘(2)和(+)(7a S)-7a-甲基-2,3的二烯胺, 5,6,7,8-六氢-1,5(1 H)-茚满二酮(12)与3-溴-2-(3-甲氧基苯基)丙烯(3)反应生成相应的5-和4-取代的烷基化分别为产品8和14a。可以通过用酸加热将8直接环化为6-甲基-D-高全麦草碱衍生物9。虽然14a可以类似地转化为相应的马来烯基甲基醚(15a),但通过初始降低5环酮功能和所得醇的乙酰化,可以在环化步骤中获得更高的收率。后面与14a的反应顺序衍生自12的化合物,可生成旋光性17β-乙酰氧基-6-甲基estra-1,3,5,7,9,14-六烯-3-醇甲基醚(15b),可用作旋光性类固醇的中心中间体。