Oxidative lactonization of oleanane and ursane acids by treating with ozone

摘要

Features of process of oxidative lactonization of 3-oxooleanolic and 3-oxoursolic acids under treatment with ozone were established. The similarity of the processes consists in generation of 3-oxooleanolic or 3-oxoursolic 13 beta,28-lactones with 12-oxo or 12-hydroxy group. In the case of ursane derivative the generation exclusively of compounds with beta-oriented 12-hydroxy group was observed, in the case of oleanane lactones prevailingly compounds with alpha-oriented 12-hydroxy group were obtained. The processes differ by the generation of the product of allylic oxidation, 3,11-dioxoursolic acid, or the isolation of the product of the lactone cycle opening with participation of the solvent, 3,12-dioxoolean-28-olic acid.