9-Hy­droxy-4,8-dimethyl-12-(piperidin-1-ylmeth­yl)-3,14-dioxatricyclo­[9.3.0.0(2,4)]tetra­dec-7-en-13-one

The title compound, C(20)H(31)NO(4), was synthesized from 9α-hy­droxy­parthenolide (9α-hy­droxy-4,8-dimethyl-12-methylen-3,14-dioxa-tricyclo­[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 is built up from fused five-and ten-membered rings with the pipyridin-1-yl-methyl group as a substituent. The ten-membered ring adopts an approximate chair–chair conformation, while the six-membered ring display a chair conformation and the five-membered ring an envelope conformation with the C(H)–C–C(H) atom at the flap. The dihedral angle between the ten-membered ring and the lactone ring is 21.7 (4)°. The mol­ecular conformation is stabilized by an O—H⋯N hydrogen bond and the crystal structure is stabilized by weak inter­molecular C—H⋯O inter­actions.