ChemInform Abstract: Synthesis and Diels‐Alder Reactions of N‐Carbalkoxydihydropyridines. Substituent Effects on the Regiochemistry of Reduction of N‐Carbalkoxypyridinium Ions.

Abstract

234ChemInform Abstract The 3-substituted pyridines (I) are reduced by various hydride-transfer reducing agents (II) in the presence of ethyl or benzyl chloroformate (III) to give various yields of the isomeric dihydropyridines (IV) and (V). (IV) and (V) are coupled with methyl acrylate (VI) to yield mixtures of the Diels-Alder adducts (VII) -(X) which are characterized by their NMR-data.