A new approach to enantiomerically pure bis-imidazoles derived from trans-1,2-diaminocyclohexane

Racemic as well as enantiomerically pure trans-1,1'-(cyclohexane-1,2-diyl)bis(imidazole N-oxides) were prepared from trans-cyclohexane-1,2-bis(methylidenamine) and 1,2-dione monooximes (alpha-hydroxyiminoketones). The enantiomeric purity of selected products was determined by means of H-1 NMR spectroscopy in the presence of (+)-(R)-(tert-butyl)(phenyl)phosphonothioic acid as a chiral solvating agent. Deoxygenation by treatment with Raney-nickel led to the corresponding chiral bis-imidazoles. (C) 2008 Elsevier Ltd. All rights reserved.