Stereoselective reduction of C-2 substituted steroid C-3 ketones with lithium tris-(R,S-1,2-dimethylpropyl)-borohydride and sodium borohydride
作者:John F. Templeton、V.P.Sashi Kumar、R.K. Gupta、Anne M. Friesen
DOI:10.1016/0039-128x(86)90020-6
日期:1986.11
the stereoselective reduction of steroid C-3 ketones with lithium tris-(R,S-1,2-dimethylpropyl)-borohydride and sodium borohydride was investigated. The C-2 mono- and di-substituted chloro and methyl derivatives were predominantly reduced to one of the epimeric alcohols. The 2 alpha-chloro and 2 alpha-methyl derivatives of 17 beta-acetoxy-5 alpha-androstan-3-one undergo stereoselective reduction with
研究了 C-2 取代对使用三-(R,S-1,2-二甲基丙基)-硼氢化锂和硼氢化钠立体选择性还原类固醇 C-3 酮的影响。C-2 单和二取代的氯和甲基衍生物主要被还原为差向异构醇之一。17 beta-acetoxy-5 alpha-androstan-3-one 的 2 α-氯和 2 α-甲基衍生物通过三-(R,S-1,2-二甲基丙基)-硼氢化锂进行立体选择性还原到轴向 (3在未取代的化合物中观察到 α) 醇,而硼氢化钠主要产生赤道 (3β) 醇。2β-氯、2β-甲基、2,2-二氯和 2,2-二甲基衍生物主要被这两种试剂还原为赤道 (3β) 醇。