organic compounds
Open access
The title compound, C23H30N2O4, a di-Mannich base derived from 4-methoxyphenol and cis-1,2-diaminecyclohexane, has a perhydrobenzimidazolidine nucleus, in which the cyclohexane ring adopts a chair conformation and the heterocyclic ring has a half-chair conformation with a C—N—C—C torsion angles of −48.14 (15) and −14.57 (16)°. The mean plane of the heterocycle makes dihedral angles of 86.29 (6) and 78.92 (6)° with the pendant benzene rings. The molecular structure of the title compound shows the presence of two interactions between the N atoms of the imidazolidine ring and the hydroxyl groups through intramolecular O—HN hydrogen bonds with graph-set motif S(6). The unobserved lone pairs of the N atoms are presumed to be disposed in a syn conformation, being only the second example of an exception to the typical `rabbit-ears' effect in 1,2-diamines.
organic compounds
Open access
The asymmetric unit of the title compound, C23H30N2O2, contains one half-molecule, with a twofold axis splitting the molecule in two identical halves. The structure of the racemic mixture has been reported previously [Rivera et al. (2009) J. Chem. Crystallogr. 39, 827–830] but the enantiomer reported here crystallized in the orthorhombic space group P21212 (Z = 2), whereas the racemate occurs in the triclinic space group P-1 (Z = 2). The observed molecular conformation is stabilized by two intramolecular O—HN hydrogen bonds, which generate rings with graph-set motif S(6). In the crystal, molecules are linked via non-classical C—HO interactions, which stack the molecules along the b axis.