Brusatol

The title compound, C(26)H(32)O(11), is composed of an α,β-unsaturated cyclo­hexa­none ring (A), two cyclo­hexane rings (B and C), a six-membered lactone ring (D) and tetra­hydro­furan 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 intra­molecular O—H⋯O hydrogen bond occurs. In the crystal, O—H⋯O hydrogen bonds involving the hy­droxy, lactone and ester groups and C—H⋯O inter­actions are observed.