The first biomimetic conversion of a germacrolide-4-epoxide into a xanthanolide

Abstract

Boron trifluoride catalysed cyclization of the germacrolide-4-epoxide dihydroparthenolide (1) provided two known guaianolides and the xanthanolide (4), the latter transformation representing the first biomimetic conversion of a germacrolide into a xanthanolide.