A One- and Two-Dimensional ¹³C and ¹H N.M.R. Study of Some Triterpenes of the Hopane, Stictane and Flavicene Groups

Abstract

The phase sensitive two-dimensional (2D) ¹³C^-1H heteronuclear correlated and double quantum filtered cosy n.m.r. spectra of the triterpenes 7β-acetoxyhopan-22-ol and 2 α,3 β,22 α- triacetoxystictane have been recorded at a resolution sufficient for the complete assignment of their proton resonances. Revisions to some of the methylene proton resonances of 7β-acetoxyhopan-22-ol proposed elsewhere are discussed, and assignments for a series of flavicene and stictane triterpenes are presented. 2D, n.m.r. analyses of a new triterpene isolated from the extracts of the lichen Pseudocyphellaria coronata revealed it to be 22 α-hydroxystictano-25,3 β lactone.