5-{[(3R,5aS,6R,8aS,9R,10S,12R,12aR)-3,6,9-Trimethylperhydro-3,12-epoxy-1,2-dioxepino[4,3-i]isochromen-10-yl]-oxymethyl}benzene-1,3-diol

Acta Cryst. (2009). E65, o358-o359 [doi.org/10.1107/S1600536809002050]

This dihydroartemisinin derivative is a fused five-ring system that has shown promising anticancer and antimalarial activity. The six-membered C₆ and C₅O rings display chair conformations. The six-membered trioxane ring has a distorted boat conformation with a C-O-O-C torsion angle of 42.55° for the peroxy group. The seven-membered ring C₆O has a distorted boat-type conformation, while the other (C₅O₂) has a distorted chair-type conformation. The structure contains intermolecular O-H...O hydrogen bonds linking the molecules into sheets parallel to the (100) planes.

W. Gul, P. Carvalho, A. Galal, M.A. Avery and M.A. El Sohly