A versatile and efficient method for the preparation of 2-alkyl
and 2-aryl-6-alkyl-2,3-dihydro-1H-pyridin-4-ones
is described. The sequence involved the condensation of β-amino
acids and t-butyl ketoester to give enaminoesters
whose intramolecular cyclisation followed by an hydrolysis step
afforded the expected products.
β-amino ester - enaminoester - dihydropyridinone - ring closure - heterocycle