Asteriscanolide. A sesquiterpene lactone with a new natural skeleton.

A sesquiterpene lactone was isolated from the hexane extract of $\text{Asteriscus aquaticus}$. Its constitution and stereochemistry were determined by spectroscopic techniques, principally two-dimensional NMR correlations (COSY, HCCORR, RELAY) and with the interpretation of certain chemical transformations. The results were confirmed by X-ray diffraction and the name asteriscane is proposed for the new natural skeleton.