5-{[(3R,5aS,6R,8aS,9R,10S,12R,12aR)-3,6,9-Trimethyl-perhydro-3,12-ep-oxy-1,2-dioxepino[4,3-i]isochromen-10-yl]oxymeth-yl}benzene-1,3-diol.

The title compound, C(22)H(30)O(7), is a fused five-ring system that is of inter-est for its anti-cancer and anti-malarial activity. The six-membered C(6) and C(5)O rings display chair conformations. The six-membered C(3)O(3) ring containing the ether and per-oxy functionalities has a distorted boat conformation, with a C-O-O-C torsion angle of 42.6 (1)° for the per-oxy group. The seven-membered C(6)O ring has a distorted boat-type conformation, while the seven-membered C(5)O(2) ring has a very distorted chair-type conformation. The structure contains inter-molecular O-H⋯O and O-H⋯(O,O) bonds that link the mol-ecules into sheets parallel to the (100) planes.