Collect. Czech. Chem. Commun. 2001, 66, 1753-1763

Synthesis of Norhydroperoxides from Natural Triterpenic Acids

Eugene S. Tatarova and Alexey V. Tkachevb,*

a Department of Organic Chemistry, Novosibirsk State University, Novosibirsk, 630090, Russia
b Novosibirsk Institute of Organic Chemistry, Academician Lavretjev Ave. 9, Novosibirsk, 630090, Russia


Treatment of triterpenoids derived from ursolic and glycyrrhetinic acids with the oxidative mixture H2O2-(CF3COO)2Hg-Na2CO3-THF results in oxidative decarboxylation. The reaction of 3O-acetylursolic acid (1) and 3O-acetyl-18β-glycyrrhetinic acid (3) affords stable norhydroperoxides, whereas decarboxylation of 3O-acetyl-11-oxoursolic acid (6) leads to unstable norhydroperoxide. The difference in properties of the norhydroperoxides is explained by the presence of a conjugated ketone, which activates the 12,13-C=C double bond for nucleophilic addition and makes possible intramolecular Michael-type addition of peroxo anion.

Keywords: NMR spectroscopy; Michael additions; Peroxides; Mercury; Terpenoids; Triterpenes; Oxidations; Decarboxylations.

References: 6 live references.