Collect. Czech. Chem. Commun.
2005, 70, 1447-1464
https://doi.org/10.1135/cccc20051447
Preparation of New Oxidized 18-α-Oleanane Derivatives
Miroslav Kvasnicaa, Iva Tišlerováa, Jan Šareka,*, Jan Sejbala and Ivana Císařováb
a Department of Organic Chemistry, Faculty of Science, Charles University, Hlavova 8, 128 43 Prague 2, Czech Republic
b Department of Inorganic Chemistry, Faculty of Science, Charles University, Hlavova 8, 128 43 Prague 2, Czech Republic
Abstract
19β,28-Epoxy-4,5-seco-3,5-cyclo-18α-olean-3(5)-ene (2) is an appropriate compound for oxidations, which lead to new oxidized compounds with potential biological activities. Several oxidations were used such as epoxidation, allylic oxidation, oxidative cleavage of double bond and other ones. From the starting compound epoxides 3a, 3b and unsaturated ketone 4 were prepared. This ketone was further oxidized to diketone 6 and anhydride 7. The double bonds of all unsaturated compounds were cleaved with ruthenium tetroxide to afford new A-seco oleananes. The structure and stereochemistry of the compounds were derived from IR, MS, 1H and 13C NMR spectra (1D and 2D COSY, TOCSY, NOESY, HSQC, HMBC).
Keywords: Triterpenes; Triterpenoids; Oleanane; Oxidation; Seco oleanane; 1H and 13C NMR spectroscopy; X-ray diffractions.
References: 30 live references.
