A method for the synthesis of 3 α,7 α,14 α-trihydroxy-5 β-cholan-24-oic acid which is a possible candidate of bile acid metabolite in vertebrates was developed. The principal reactions involved were 1) stereoselective remote-hydroxylation of methyl ursodeoxycholate diacetate with dimethyldioxirane, 2) site-selective protection at C-3 by tert- butyldimethylsilylation of the resulting 3 α,7 α,14 α-trihydroxy ester, 3) oxidation of the diol with pyridinium dichromate adsorbed on activated alumina, 4) stereoselective reduction of the 7-ketone with zinc borohydride, and 5) cleavage of the protecting group at C-3 with p-toluenesulfonic acid. A facile elimination of the 14 α-hydroxy group under an acidic or neutral condition is also described. The synthetic reference compound is now available for comparison with unidentified biliary bile acids detected in vertebrate bile.
ASJC Scopus subject areas
- 化学 (全般)