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.
- 3 α,7 α,14 α-trihydroxy-5 β-cholan-24-oic acid
ASJC Scopus subject areas
- Drug Discovery