5,9-Dihydroxy-9-methyl-3,6-dimethylene-3a,4,5,6,6a,7,8,9,9a,9b-decahydroazuleno[4,5-b]furan-2(3H)-one

Abstract

The title compound, C15H20O4, was synthesized from 9α-hydroxyparthenolide (9α-hydroxy-4,8-dimethyl-12-methylene-3,14-dioxatricyclo[9.3.0.02,4]tetradec-7-en-13-one), which was isolated from the chloroform extract of the aerial parts of Anvillea radiata. The seven-membered ring has a chair conformation, while the five-membered rings display twisted conformations. The dihedral angle between the seven-membered ring and the lactone ring is 21.69 (10)°. In the crystal, molecules are linked into chains propagating along the c axis by intermolecular O—H...O hydrogen bonds; an intramolecular O—H...O link also occurs.