Received 5 July 2010
The title compound, C18H26O7, is an eremophilenolide which has been isolated from the plant Ligularia duciformis for the first time. The present study confirms the atomic connectivity assigned on the basis of 1H and 13C NMR spectroscopy. The molecule contains three fused rings, two six-membered rings in chair confomations and a five-membered ring in a flattened envelope conformation. Two hydroxy groups are involved in formation of intra- and intermolecular O-HO hydrogen bonds. The latter ones link molecules into chains propagating in .
Data collection: RAPID-AUTO (Rigaku, 2000); cell refinement: RAPID-AUTO; data reduction: CrystalStructure (Rigaku/MSC, 2000); program(s) used to solve structure: SHELXS97 (Sheldrick,2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: CV2743 ).
The project was supported by the 985 Project (MUC985) Minzu University of China, and the Major Project for Young Teachers in Minzu University of China CUN10A, together with the `Programme of Introducing Talents of Discipline to Universities' (B08044), and the `Project for Scientific and Technical Achievements in Industrialization', Beijing Education Commission.
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