Dimerization of Butenolide Structures. A Biomimetic Approach to the Dimeric Sesquiterpene Lactones (±)-Biatractylolide and (±)-Biepiasterolide

The biomimetic synthesis of the bisesquiterpene lactones (±)-biatractylolide 1 and (±)-biepiasterolide
2 via dimerization of the captodative stabilized radical 8 is reported. Atractylon 7 has also been
shown to be a possible intermediate during the biosynthesis of biatractylolide 1, biepiasterolide 2,
atractylolide 3, and hydroxyatractylolide 4.