Diels-Alder cycloaddition approach to puupehenone-related metabolites: Synthesis of the potent angiogenesis inhibitor 8-epipuupehedione

A new synthetic strategy toward puupehenone-related bioactive metabolites from sclareol oxide, based on a Diels-Alder cycloaddition approach, is described. Utilizing this, marine ent-chromazonarol and the potent angiogenesis inhibitor 8-epipuupehedione have been synthesized.