text: The mechanism of the Kröhnke pyridine synthesis begins with enolization of α-pyridinium methyl ketone 4 followed by 1,4-addition to the α, β-unsaturated ketone 5 to form the Michael adduct 6, which immediately tautomerizes to the 1,5-dicarbonyl 7. Addition of ammonia to 7 followed by dehydration via 8 generates the imine intermediate 9., The imine intermediate is then deprotonated to enamine 10 and cyclizes with the carbonyl to generate intermediate 11. The pyridinium cation is then eliminated to form hydroxy-dienamine 12. Aromatization of 12 via subsequent loss of water generates the desired pyridine heterocycle 13.