SYNTHESIS AND STRUCTURAL STUDY ON Α-SUBSTITUED-1-STYRYLPYRIDINIUM SALTS. REINVESTIGATION OF KROHNKE CONDENSATION

Article abstract of DOI:10.1016/S0040-4020(01)87473-1

Kroehnke condensation of several cycloimmonium salts with p-dimethylaminobenzaldehyde has been studied.X-Ray diffraction, IR and Raman spectra, 1H- and 13C-NMR and UV spectra of the products are discussed, being compared, when necessary, with the starting pyridinium salts.All compounds showed the Z configuration, corresponding to the more stable structure, except one, in which steric factors were predominant.