ON THE REGIOSELECTIVITY OF THE REACTION OF N-METHOXYCARBONYLPYRIDINIUM CHLORIDE WITH GRIGNARD REAGENTS: HIGHLY REGIOSELECTIVE SYNTHESIS OF 2-SUBSTITUTED N-METHOXYCARBONYL-1,2-DIHYDROPYRIDINES.

Article abstract of DOI:10.1016/S0040-4039(00)81774-8

Whereas alkyl Grignard reagents undergo 1,2- and 1,4-additions to N-methoxycarbonyl-pyridinium chloride in a variable ratio, alkenyl and alkynyl Grignard reagents do the exclusive 1,2-addition to afford 2-substituted N-methoxycarbonyl-1,2-dihydropyridines in fair to excellent yields.