Configuration of 1,10-epoxyguaianolides: stereochemistry of 1,10-epoxy-8α-hydroxyachillin
Abstract
The stereochemistry of 1,10-epoxy-8α-hydroxyachillin (2a) has been established on the basis of its chemical transformation into 8α-acetoxy-1,10β-epoxy-3,4-dihydroachillin (7b), together with the indirect conversion of 8α-acetoxyachillin (3a) into the 8α-acetoxy-1,10β- and -α-epoxy-3,4-dihydroachillins (7b) and (7a). The structure of the latter compound has been determined by X-ray analysis.