Regiospecific Nucleophilic Attack at the γ‐Position of 1‐(2,6‐Dimethyl‐4‐oxo‐1,4‐dihydro‐1‐pyridyl)pyridinium Compounds; Novel Synthesis of 4‐Substituted Pyridines

Syntheses of 4-substituted pyridines (3) are always of interest. In the pyridinium ion (1) positions 2 and 6 are sterically shielded; it therefore reacts at the activated position 4 with C, N and S nuleophiles in high yields to give (2), which is readily cleaved to (3) and (4), or decomposes to these products.