Collect. Czech. Chem. Commun. 1989, 54, 1036-1042
https://doi.org/10.1135/cccc19891036

Conversion of betulin into careyagenolide (2α,3β-dihydroxy-18α,19βH-ursan-28,20β-olide)

Jan Sejbala, Eva Klinotováa, Markéta Bludskáa, Jiří Klinota and Miloš Buděšínskýb

a Department of Organic Chemistry, Charles University, 128 40 Prague 2
b Institute of Organic Chemistry and Biochemistry, Czechoslovak Academy of Sciences, 166 10 Prague 6

Abstract

Careyagenolide (I) and its respective 2β,3α- and 2β,3β-isomers XVII and XIV were prepared from 3-oxo-18α,19βH-ursan-28,20β-olide (IX), accessible from betulin (II). The key step of the synthesis was hydroxylation of ketones IX and X with 3-chloroperoxybenzoic acid and reduction of ketones XI-XIII.