Palladium (II) catalyzed regioselective lactonization of steroids. Chemoselective construction of novel estrone derivatives
作者:L. Troisi、G. Vasapollo、B. El Ali、G. Mele、S. Florio、V. Capriati
DOI:10.1016/s0040-4039(99)00094-5
日期:1999.2
Palladium acetate and 1,4-bis(diphenylphosphino)butane (dppb) catalyze regioselective cyclocarbonylation of 4-allylsteroids forming exclusively 7-membered ring lactones with excellent yields (96–98 %). The stereoselective addition of an epoxide ring on the side-chain of steroids is realized by coupling the carbonyl group of the cyclopentanone ring of the steroid with 2-benzothiazolylchloromethyllithium
乙酸钯和1,4-双(二苯基膦基)丁烷(dppb)催化4-烯丙基类固醇的区域选择性环羰基化,形成仅7元环内酯,产率极高(96–98%)。通过将甾族化合物的环戊酮环上的羰基与2-苯并噻唑基氯甲基锂1或4,4-二甲基-2-恶唑啉基氯代烷基22和3偶联,可以在甾族化合物的侧链上立体选择性地加成环氧化物。