Regioselective oxidation of cholic acid and its 7ß epimer by using o-iodoxybenzoic acid.

Rational exploration directed by DFT (density functional theory) based atomic Fukui indices, lead to development of regioselective oxidation of cholic acid and its 7ß epimer by o-iodoxybenzoic acid. In case of cholic acid only, 7α-hydroxyl underwent oxidation, where as in its 7ß epimer the selectivity was towards 12α-hydroxy group. Since these oxidations are the key steps in synthesis of ursodeoxycholic acid starting from cholic acid these findings may be useful in devising a protection free synthetic route.