Absolute Configurations and Circular Dichroism of Sesquiterpene-Coumarin Ethers

Article abstract of DOI:10.1007/BF00798650

The absolute stereochemistry of 14 naturally occurring sesquiterpene-coumarin ethers is discussed.In 13 cases the coumarin moiety is isofraxidin (7-hydroxy-6,8-dimethoxycoumarin), in one case scopoletin (7-hydroxy-6-methoxycoumarin).The sesquiterpene moieties belong either to the bicyclic drimenole series or to its consecutive products (methyl migration, ring opening).The CD spectra of all compounds are given.The assignments of the absolute configurations are based on the method of Horeau, chemical correlation by degradation reactions, extensive comparison of CD data, and biogenetic considerations. - (Keywords: Achillea; Artemisia; Chiroptical properties; Horeaus's method; Natural constituents)