Potential Bile Acid Metabolites. 25. Synthesis and Chemical Properties of Stereoisomeric 3.ALPHA.,7.ALPHA.,16- and 3.ALPHA.,7.ALPHA.,15-Trihydroxy-5.BETA.-cholan-24-oic Acids.

Abstract

Epimeric 3a a,7a a,16-and 3a a,7a a,15-trihydroxy-5b b-cholan-24-oic acids and some related compounds were synthesized from chenodeoxycholic acid (CDCA) and ursodeoxycholic acid (UDCA), respectively. The key reaction involved one-step remote oxyfunctionalization of unactivated methine carbons at C-17 of CDCA and at C-14 of UDCA as their methyl ester-peracetate derivatives with dimethyldioxirane (DMDO). After dehydration of the resulting 17a a-and 14a a-hydroxy derivatives with POCl 3 or conc. H 2 SO 4 , the respective D D 16 -and D D 14 -unsaturated products were subjected to hydration via hydroboration followed by oxidation to yield the 3,7,16-and 3,7,15-triketones, respectively. Stereoselective reduction of the respective triketones with tert-butylamine-borane complex afforded the epimeric 3a a,7a a,16-or 3a a,7a a,15-trihydroxy derivatives exclusively. A facile formation of the corresponding e e-lactones between the side chain carboxyl group at C-24 and the 16a a-(or 16b b-) hydroxyl group in bile acids is also clarified.

Bile salts of vertebrates: structural variation and possible evolutionary significance

“…We note the synthetic efforts of the laboratory of G. Salen ( 34 ) and T. Iida ( 35,36 ) who has developed new methods for synthesizing natural bile acids. We also acknowledge the extensive work on bile acid metabolism by Swedish workers in the school of bile acids launched by the late Sune Bergstrom ( 37 ) and continued by his pupils such as Sjövall ( 38 ) ( 22 ).…”

“…Bile acids and bile alcohols were then converted to their per-acetates or per-TMS derivatives. To establish the location and orientation of hydroxyl groups in novel bile acids, proton and 13 C nuclear magnetic resonance analyses were used in a continuing collaboration with T. Iida of Nihon University ( 35,36,45,46 ). Supplemental Material can be found at:…”

Novel Bile Acids from Bear Bile Powder and Bile of Geese

“…[4][5][6][7][8][9] In the previous study, several bile acids including CDCA, CA, TCDCA, TUDCA, TCA were obtained from bile of Ursus arctos by Yamaguchi et al 10) In order to search for new natural bioactive constituents from animal bile and provide chemical standards for the research on its quality control, two kinds of bile from different animals including Selenaretos thibetanus CUVIER and Anser anser domesticus were chemically investigated in our research group. This paper describes the isolation and structural determination of two novel bile acids, tauroselocholic acid (1), tauroansocholic acid (2), and a new natural bile acid, cygnocholic acid (3) which had been synthesized by Iida et al,11) together with seven known compounds from these two kinds of bile.…”

Synthesis of 3.ALPHA.,7.ALPHA.,14.ALPHA.-Trihydroxy-5.BETA.-cholan-24-oic Acid: A Potential Primary Bile Acid in Vertebrates

“…Hydroxylation at the C-5 (b-OH) position has been reported to occur in the biliary bile acids of the pheasant, 1) and 5b-hydroxylation of analogous nor-CDCA was demonstrated in hamster liver.…”

“…1) In the most recent work, Hagey et al 10) have reported the existence of the 3a,7a,16a-trihydroxy acid as a primary bile acid in many species of birds such as herons (Ardeidae), pelicans (Pelecanidae) and owls (Tytonidae).…”