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organic compounds
In the title compound, 9-(3-furyl)-1,4,4a,5,9,10,10a,10b-octahydro-4-hydroxy- 4a,10a-dimethyl-1,4-etheno-3H,7H-benzo[1,2-c:3,4-c′]dipyran-3,7-dione, C20H20O6, the pyran ring adopts a conformation intermediate between sofa and half-chair. All other six-membered rings are in the boat conformation. The furan ring is planar and is equatorially attached. The crystal structure is stabilized by O—HO and C—HO intermolecular hydrogen bonds.