4-(4-Hy-droxy-phenyl)-2,2,4-trimethyl-7,8-benzo-thia-chroman, a fused-ring counterpart of thia-Dianin's compound.

The title compound, C22H22OS [systematic name: 4-(1,3,3-trimethyl-2,3-di-hydro-1H-4-thia-phenanthren-1-yl)phenol], crystallizes unsolvated from nitro-methane as colourless prisms (m.p. 425-427 K) in the polar monoclinic space group Ia with Z' = 2 (mol-ecules A and B). Both independent mol-ecules possess a very similar proximal conformation, this referring to the juxtaposition of the 4-hy-droxy-phenyl substituent with respect to the syn-related methyl group. In the crystal, mol-ecule A is linked to mol-ecule B by an O-H⋯O hydrogen bond. In turn, mol-ecule B exhibits a weak O-H⋯π inter-action with the phenolic group of mol-ecule A related by a-glide symmetry. Together, these lead to [100] chains.