Brusatol

The title compound, C(26)H(32)O(11), is composed of an α,β-unsaturated cyclo-hexa-none ring (A), two cyclo-hexane rings (B and C), a six-membered lactone ring (D) and tetra-hydro-furan ring (E). Ring A exists in a half-chair conformation with a C atom displaced by 0.679 (2) Å from the mean plane through the remaining five atoms. Ring B exists in a normal chair conformation. Both rings C and D exist in a twisted-chair conformation due to the O-atom bridge and the carbonyl group in rings C and D, respectively. Ring E shows an envelope conformation with a C atom displaced by 0.761 (1) Å from the mean plane through the remaining five atoms. The ring junctions are A/B trans, B/C trans, C/D cis and D/E cis. An intra-molecular O-H⋯O hydrogen bond occurs. In the crystal, O-H⋯O hydrogen bonds involving the hy-droxy, lactone and ester groups and C-H⋯O inter-actions are observed.