Modified bile acids: Preparation of 7α,12α-dihydroxy-3β- and 7α,12α-dihydroxy-3α-(2-hydroxyethoxy)-5β-cholanic acid and their biological activity

Article abstract of DOI:10.1016/0040-4039(92)88048-A

Methodology for the preparation of 7α-12α-dihydroxy-3β- (2) and 7α,12α-dihydroxy-3α-(2-hydroxyethoxy)-5β-cholanic acid (3) is described. Nucleophilic displacement of the 3-mesylate of unprotected cholic acid with ethylene glycol led to the 3β-isomer whereas the 3α-isomer was synthesized via the 7,12-diacetyl protected 3-allyl ether of methyl cholate. Only the 3α-isomer 3 is recognized by the ileal bile acid transport system with affinity comparable to cholic acid.