Collect. Czech. Chem. Commun.
2001, 66, 1753-1763
https://doi.org/10.1135/cccc20011753
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
Abstract
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.
