Stolonilactone, a novel terpenoid-related compound, isolated from the Okinawan soft coral Clavularia koellikeri

A novel terpenoid-related compound, stolonilactone (1), was isolated from the Okinawan soft coral Clavularia koellikeri. The structure of 1 was elucidated on the basis of spectroscopic analysis. A possible biogenesis of 1 through the [4 + 2]-cycloaddition of a trisnorsesquiterpenoid-type diene and a cembranolide-type dienophile is proposed.