Structural characterization of (±)-3-aryl-1-azabicyclo[2.2.2]octan-3-ols by two-dimensional NMR spectroscopy and X-Ray crystallography. I

Abstract

A series of (±)-3-aryl-1-azabicyclo[2.2.2]octan-3-ols were synthesized and studied by 1H, 13C and 2D NMR spectroscopy, and the crystal structure of (±)-3-(4-methylphenyl)-1-azabicyclo[2.2.2]octan-3-ol was determined by X-ray diffraction. The combined use of COSY, NOESY and 1H–13C correlation spectra of these compounds helped in the unambiguous and complete assignments of the bicyclic carbon and proton spin system. This study allows the establishment of the proton magnetic parameters for the quinuclidine moiety. Standard values of 1H1H coupling constants are proposed in order to analyse more complex quinuclidine derivatives.