The preparation of some derivatives of glycyrrhetic acid and oleanolic acid.

Some new derivatives of glycyrrhetic acid and oleanolic acid were prepared and characterized. Various combinations of the modified and normal functional groups were synthesized as required for a separate study of the uncoupling activities of glycyrrhetic acid and oleanolic acid. The hydroxyl functions of these two acids were modified to β-carboxypropionyl, acetyl and β-methoxycarbonylpropionyl esters. The carboxyl function of glycyrrhetic acid was converted to amide, p-amidobenzoic acid, o-amidobenzoic acid and the glycine conjugate of the acid. 11-Deoxy (glycyrrhetic acid) and 9,11-dehydro-11-deoxo (from both acids) analogues were prepared. 11-Oxo analogues of oleanolic acid were synthesized as well as the methyl esters.