9-(2-Hy­droxy-6-oxocyclo­hex-1-en-1-yl)-2,3,4,9-tetra­hydro-1H-xanthen-1-one

In the xanthene ring system in the title compound, C(19)H(18)O(4), the 4H-pyran ring has a maximum deviation of 0.110 (2) Å from planarity and the cyclo­hexene ring exhibits a puckered conformation [puckering parameters Q (T) = 0.452 (3) Å, θ = 57.0 (4) and ϕ = 131.7 (4)°]. The cyclo­hexene ring attached to the xanthene system adopts an envelope conformation, with the middle of the three methylene C atoms as the flap atom. In the crystal, O—H⋯O and C—H⋯O hydrogen bonds form infinite chains of R (1) (2)(6) ring motifs along [100] with the xanthene groups arranged in an alternating zigzag manner.