The first spontaneous resolution of a sulfoxide: Dianin's compound analogue, (R)-4-(4-hydroxyphenyl)-2,2,4-trimethylthiachroman-1-oxide

The title sulfoxide, C18H20O2S, was prepared by controlled oxidation of thia-Dianin's compound using hydrogen peroxide in glacial acetic acid. On recrystallization from glacial acetic acid, it was found to form unsolvated, spontaneously resolved crystals, the initial crystal structure analysis revealing the presence of both sulfoxide epimers in the crystal. On multiple recrystallization a single epimer was observed, with crystallization occurring in the unchanged orthorhombic space group P212121, with Z′ = 1. The molecule possesses a distal conformation, referring to the juxtaposition of the p-hydoxyphenyl substituent with respect to its syn-related methyl group, with the sulfoxide oxygen atom anti to the aromatic substituent. The molecular packing features O—H...O hydrogen bond chains running parallel to the b axis of the unit cell.

4-(4-Hydroxyphenyl)-2,2,4-trimethyl-7,8-benzothiachroman, a fused-ring counterpart ofthia-Dianin's compound

The title compound, C22H22OS [systematic name: 4-(1,3,3-trimethyl-2,3-dihydro-1H-4-thiaphenanthren-1-yl)phenol], crystallizes unsolvated from nitromethane as colourless prisms (m.p. 425–427 K) in the polar monoclinic space groupIawithZ′ = 2 (moleculesAandB). Both independent molecules possess a very similarproximalconformation, this referring to the juxtaposition of the 4-hydroxyphenyl substituent with respect to thesyn-related methyl group. In the crystal, moleculeAis linked to moleculeBby an O—H...O hydrogen bond. In turn, moleculeBexhibits a weak O—H...π interaction with the phenolic group of moleculeArelated bya-glide symmetry. Together, these lead to [100] chains.

Total CCl4 guest alignment in a quasiracemic clathrate closely related to Dianin's compound

In the trigonal CCl4quasiracemic clathrate, space group R3, formed from host components S-(−)-Dianin's compound, 4, and its (+)-2R,4R 2-nor methyl analogue, 2, the unprecedented complete ordering of a C–Cl bond of the guest with respect to the c-axial direction and the participation of an unexpected host conformation is reported for the first time.