 The method is named after Dr. Fritz Kröhnke.In his work at the University of Giessen, Kröhnke observed condensation of α-pyridinium methyl ketone salts 1 with α,β-unsaturated carbonyl compounds 2 via a Michael reaction when treated with ammonium acetate to give 2,4,6-trisubstituted pyridines in high yields under mild reaction conditions.The proposed intermediates, 1, 5-dicarbonyl compound 3, have not been isolated.