9-(2-Chlorophenyl)-4a-hydroxy-3,4,4a,5,6,7,9,9a-octahydro-2H-xanthene-1,8-dione

Crystal structure of 10a-hy-droxy-9-(3-nitro-phen-yl)-3,6-diphenyl-3,4,5,6,7,8a,9,10a-octa-hydro-1H-xanthene-1,8(2H)-dione

In the octa-hydroxanthenedione unit of the title compound, C31H27NO6, the central di-hydro-pyran ring shows an envelope conformation, while the bilateral cyclo-hexene and cyclo-hexane rings adopt a half-boat conformation and a chair conformation, respectively. The nitro-benzene ring is twisted with respect to the two benzene rings, making dihedral angles of 63.1 (1) and 63.0 (1)°. In the crystal, O-H⋯O hydrogen bonds link the mol-ecules into supra-molecular chains propagating along the a-axis direction.