Collect. Czech. Chem. Commun.
1987, 52, 2744-2752
https://doi.org/10.1135/cccc19872744
E-seco-Acids of pentacyclic triterpenoids. Oxidative cleavage of ring E in 3β-acetoxy-21-oxo-18α,19βH-ursan-28→20β-olide
Eva Klinotová, Helena Pavlíková, Martina Pressová, Hana Chodounská, Jiří Klinot, Jiří Protiva and Alois Vystrčil
Department of Organic Chemistry, Charles University, 128 40 Prague 2
Abstract
Oxidative cleavage of 3β-acetoxy-22-hydroxymethylene-21-oxo-18α,19βH-ursan-28→20β-olide (VII) and 3β-acetoxy-21,22-dioxo-18α,19βH-ursan-28→20β-olide (VIII) afforded primarily the E-seco-acid XII which was converted into acids XVI and XX, isomeric at the C(17) carbon atom. Configuration of these acids has been determined.
