Regioselective Synthesis of 4-Alkylpyridines from Pyridine and Aldehydes via Dipole Reversal Process of 1,4-Dihydropyridine Phosphonate

4-Alkylation of pyridine has been accomplished by the reaction of ylides, derivated from 1,4-dihydropyridine phosphonate via phosphonioalkoxycarbonylation of pyridine with aldehydes and subsequent elimination of diisopropyl phosphate followed by aromatization with potassium tert-butoxide.