Potential bile acid metabolites. 19. The epimeric 3 alpha,6,7 beta-trihydroxy- and 3 alpha,6,7 beta,12 alpha-tetrahydroxy-5 alpha-cholanoic acids.
Syntheses by a new procedure of the known 3 alpha,6 alpha,7 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 appropriate 6-bromo-7-oxo derivatives of the corresponding 5 beta-acids. Successful reduction of the 6,7-ketols to the desired products depended on the proper choice of reagents, either Zn(BH4)2 or Li/NH3/MeOH.
College of Engineering, Nihon University, Fukushima, Japan.
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Iida
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Nishida
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Chang
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Niwa
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Goto
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Nambara
D000641:Ammonia; D001647:Bile Acids and Salts / Q000378:metabolism*; D001894:Borohydrides; D002757:Cholanes / Q000138:chemical synthesis*; D002793:Cholic Acids / Q000138:chemical synthesis*; D007202:Indicators and Reagents; D008094:Lithium; D000432:Methanol; D015032:Zinc
D001647:Bile Acids and Salts; D001894:Borohydrides; D002757:Cholanes; D002793:Cholic Acids; D007202:Indicators and Reagents; C004821:muricholic acid; C035925:3,6,7,12-tetrahydroxycholanoic acid; D000641:Ammonia; D008094:Lithium; D015032:Zinc; D000432:Methanol