Oxidation of the hydroxyl group (C-3 -OH) of ursolic acid [oleanolic acid], isolated from methanolic extract of tembesu fruit, had been done using Jones’ reagent (C1O3/H2SO4/H2O) in acetone with 40% yield. Spectrum data of ]H-NMR showed that the methine proton at C-3 position of the triterpenoids was no longer existed, and the analysis of mass spectrum showed that the oxidation products had m…