New humulene derivatives from asteriscus graveolens

The aerial parts of Asteriscus graveolens afforded in addition to asteriscunolides A, B, C and D twelve further humulene derivatives, two bicyclic compounds also derived from humulene, a bisabolene derivative and the diisovalerate of coniferyl alcohol. The structures and the configurations of these compounds were determined mainly by spectroscopic methods. The problem of the proposed isolation of “stable conformers” of the asteriscunolides is discussed.