9-Hydroxy-4,8-dimethyl-12-(pyrrolidin-1-ylmethyl)-3,14-dioxatricyclo[9.3.0.02,4]tetradec-7-en-13-one

Abstract

The title compound, C19H29O4, was synthesized from 9α-hydroxyparthenolide (9α-hydroxy-4,8-dimethyl-12-methylen-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 molecule is built up from two fused five- and ten-membered rings with the pyrrolidin-1-ylmethyl group as a substituent. The five-membered lactone ring has an envelope conformation, whereas the ten-membered and pyrrolidine rings display approximate chair–chair and twisted conformations, respectively. The dihedral angle between the ten-membered ring and the lactone ring is 18.01 (19)°. An intramolecular O—H...N hydrogen bond occurs. The crystal structure is stabilized by weak intermolecular C—H...O hydrogen-bonding interactions.