The synthetic study of the aza-annulation reaction of enamines and further decarbTHE SYNTHETIC STUDY OF THE AZA-ANNULATION REACTION OF ENAMINES AND FURTHER DECARBOXYLATIVE MODIFICATIONSoxylative modifications

Abstract

Aza-annulation of enamines generated from β-ketoester using maleic and itaconic anhydrides produces functionalized γ- and δ-lactams with good diastereoselectivity. Subsequent hydrolysis of the aza-annulation products yielded dicarboxylic acids, which are susceptible to further decarboxylation. Simultaneous migration of the C=C double bond occurs during the decarboxylation of β-γ unsaturated carboxylic acids with an electron-rich enamide double bond. This provides a straightforward synthesis route towards 1,2,3,4-tetrahydropyridine-2-ones and 3-pyrrolin-2-ones.