Author:
Sejbal Jan,Klinot Jiří,Vystrčil Alois
Abstract
19β,28-Epoxy-18α-oleanan-3-one (I), 19β,28-epoxy-24-nor-18α-oleanan-3-one (XIV) and 3-lupanone (XVII) are hydroxylated with 3-chloroperoxybenzoic acid in the presence of methanol or ethanol and 0.01-0.1% of sulfuric acid in position 2α. Hydroxy ketones VII, XV, and XVI are formed, respectively. The reaction is sensitive to the concentration of sulfuric acid; beyond this concentration range predominantly various 3,4-seco derivatives are formed (for example VI, IX, X, XVIII). 2-Oxo derivative IV is hydroxylated in a similar manner, giving rise to 3α-hydroxy-2-ketone VIII, while 1-oxo derivative XIII does not react. A reaction path is proposed for the hydroxylation, comprising the enol form or the enol ether as an intermediate.
Publisher
Institute of Organic Chemistry & Biochemistry
Cited by
10 articles.
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