Potential bile acid metabolites. 19. The epimeric 3α,6,7β-trihydroxy-and 3α,6,7β,12α-tetrahydroxy-5α-cholanoic acids
作者:Takashi Iida、Shinji Nishida、Frederic C. Chang、Toshifumi Niwa、Junichi Goto、Toshio Nambara
DOI:10.1016/0039-128x(93)90061-q
日期:1993.4
beta- and 3 alpha,6 beta,7 beta-trihydroxy-5 alpha-cholanoic acids, and of the once-reported analog 3 alpha,6 alpha,7 beta,12 alpha-, as well as the new 3 alpha,6 beta,7 beta,12 alpha-tetrahydroxy-5 alpha-cholanoic acids, are described. Key intermediates of the syntheses are the 6-oxo-7 beta-ols of the respective 5 alpha-cholanoic acids (and their methyl esters) prepared by allomerization at C-5 of
通过已知的 3 alpha,6 alpha,7 beta- 和 3 alpha,6 beta,7 beta-trihydroxy-5 alpha-cholanoic 酸和曾经报道的类似物 3 alpha,6 alpha,7 beta 的新程序合成,12 alpha-,以及新的 3 alpha,6 beta,7 beta,12 alpha-tetrahydroxy-5 alpha-cholanoic 酸。合成的关键中间体是相应 5 α-胆酸(及其甲酯)的 6-oxo-7 β-ols,通过相应 5 的适当 6-bromo-7-oxo 衍生物的 C-5 异构化制备。 β-酸。将 6,7-酮醇成功还原为所需产物取决于试剂的正确选择,无论是 Zn(BH4)2 还是 Li/NH3/MeOH。