Winolides A–C, bioactive sesquiterpene lactones with unusual 5,6-secoeudesmane frameworks from Inula wissmanniana†
Abstract
Winolides A–C (1–3), three bioactive sesquiterpene lactones with irregular 5,6-secoeudesmane frameworks, which probably arise from different dienol-benzene rearrangements, were isolated from Inula wissmanniana. Their structures and absolute configurations were established by extensive analysis of spectroscopic data, computational methods, and asymmetric synthesis.