10α-Hydroxy-4,9-dimethyl-13-[(4-phenylpiperazin-1-yl)methyl]-3,8,15-trioxatetracyclo[10.3.0.02,4.07,9]tetradecan-14-one

The title compound, C25H34N2O5, was synthesized from 9 alpha-hydroxyparthenolide (9 alpha-hydroxy-4,8-dimethyl-12-methylene-3,14-dioxatricyclo[9.3.0.0(2,4)]tetradec-7-en-13-one), which was isolated from the chloroform extract of the aerial parts of Anvillea radiata. The molecule contains a fused five-and ten-membered ring system. The ten-membered ring adopts an approximate chair-chair conformation, while the five-membered ring is in an envelope conformation, with the C atom closest to the hydroxy group forming the flap. The piperazine ring is in a chair conformation. In the crystal, O-H center dot center dot center dot O hydrogen bonds connect molecules into chains along [100]. Weak intermolecular C-H center dot center dot center dot O hydrogen bonds are also present.