Nitrile and non-nitrile pyridine products from the reaction of 2-cyano- 3-(x-nitrophenyl)prop-2-enamides with methyl 3-oxobutanoate

The reaction of 2-cyano-3-(x-nitrophenyl)prop-2-enamides with methyl 3-oxobutanoate affords methyl 4-aryl-3-cyano-6-methyl-2-oxo-1,2-dihydropyridine-5-carboxylates, methyl 4-aryl-5-cyano-2-hydroxy-2-methyl-6-oxopiperidine-3-carboxylates, methyl 4-aryl-3-carbamoyl-6-methyl-2-oxo-1,2,3,4-tetrahydropyridine-5-carboxylates (the molecular structure of one of which has been confirmed by X-ray diffraction) and methyl 4-aryl-3-hydroxy-6-methyl-2-oxo-1,2-dihydropyridine-5-carboxylates