4,4'-Dimeth-oxy-2,2'-{[(3aRS,7aRS)-2,3,3a,4,5,6,7,7a-octa-hydro-1H-1,3-benzimidazole-1,3-diyl]bis(methyl-ene)}diphenol.

The title compound, C(23)H(30)N(2)O(4), is a Mannich base useful for studying the effect of an electron-donating phenol substituent on intra-molecular hydrogen bonding. In the mol-ecular structure, the cyclo-hexane ring adopts a chair conformation and the five-membered ring has a twisted envelope conformation. Each meth-oxy group is oriented in the same plane of the respective aromatic ring, showing torsion angles below 11.8†(3)° and bond angles between the meth-oxy group and the aromatic ring of 116.6†(2) and 116.6†(1)°. The structure shows inter-actions between two the N atoms of the heterocyclic ring and the hy-droxy groups by intra-molecular O-H⋯N hydrogen-bonding inter-actions. In the crystal, C-H⋯O inter-actions are observed. The crystal studied was a racemic mixture of RR and SS enanti-omers.