title: Cycloetherification of hydroxyoleanenes by N-bromosuccinimide.
abstract: Treatment of 28-hydroxyolean-12-enes with N-bromosuccinimide (NBS) in acetonitrile at room temperature afforded 12 alpha-bromooleanan-13beta, 28-epoxides in high yield. This reaction resulted in the formation of olean-9 (11), 12-diene-18alpha, 29-epoxides from 29-hydroxy isomers but recovered only starting materials from 30-hydroxy isomers. NBS will be used a reagent for diagnostic tool to distinguish between isomers bearing a primary hydroxyl group on D/E rings of olean-12-enes.
authors.affiliation: Natural Products Research Institute, Seoul National University, Seoul 110, Korea.
authors.forename: W S
authors.initials: WS
authors.lastname: Woo
authors.forename: S S
authors.initials: SS
authors.lastname: Kang
authors.forename: S S
authors.initials: SS
authors.lastname: Jew