Abstracto
- A reinvestigation of the aerial parts ofHebeclinium macrophyllum afforded in addition to known compounds several further seco-labdane derivatives; all being epimeric pairs at C-5. The structures were elucidated by high field NMR techniques. The stereochemistry was assigned by NOE difference spectroscopy and the absolute configurations were deduced from the Cotton-effects of the natural compounds and of chemical transformation products.