Synthesis, modification and biological activity of 2,3-indoles of Glycyrrhetinic acid.

The synthesis of 2,3-indoles of Glycyrrhetinic acid (GLA) and its methyl ester was carried out by the Fischer reaction. Reductive transformations of GLA methyl ester 2,3-indole were carried out to obtain 11-deoxo- and 9,12-diene analogs. N-methylation of 2,3-indole gave N-methyl-indole-11-oxo-18β-olean-12-en-30-oic acid.