The title oxazolidine compound, C27H39NO2, was synthesized from N-isopropyl­norephedrine. The dihedral angle between the aromatic rings is 70.33 (5)°. The N atom of the heterocycle is oriented to allow intra­molecular O—H⋯N hydrogen bonding with the hydr­oxy substituent.

In the title compound, C23H31NO2, the lone pair on the nitro­gen atom is oriented to facilitate intra­molecular hydrogen bonding with the hydr­oxy group residing on the phenyl substituent. The five-membered ring adopts an envelope confornmation with the O atom at the flap. The absolute stereochemistry was verified by measurement of optical activity using a digital polarimeter.

The title compound, C21H27NO2, exhibits hydrogen bonding between the phenolic H atom and the heterocyclic N atom. The absolute configuration of the mol­ecule is known from the synthetic procedure.

Key indicators: single-crystal X-ray study; T = 193 K; mean (C-C) = 0.002 Å; R factor = 0.028; wR factor = 0.076; data-to-parameter ratio = 17.0.The title molecule, C 13 H 18 N 2 OS, is an oxadiazinanthione derived from (1R,2S)-norephedrine. There are two molecules in the asymmetric. Both adopt roughly half-chair conformations; however, the 5-position carbon orients out of opposite faces of the oxadiazinanthiones plane in the two molecules. In the crystal structure, they are oriented as a dimer linked by a pair of N-HÁ Á ÁS hydrogen bonds. The absolute configuration has been established from anomalous dispersion and confirms the known stereochemistry based on the synthetic procedure. Related literature

The title compound, C16H22N2O3, was synthesized during the course of a study on (1R,2S)-norephedrine-derived 1,3,4-oxadiazinan-2-ones. The conformation adopted by the isopropyl group is pseudo-axial relative to the oxadiazinan core. The allylic strain contributes to this conformational arrangement.