Reaction of N-methyldihydropyridines with alkoxycarbene complexes of chromium and tungsten: sequential use of three carbonyl ligands of Cr(CO)6 for the formation of polyoxygenated compounds

Abstract

N-methylpyridinium ylide complexes obtained from alkoxycarbene complexes of chromium and N-methyldihydropyridines easily insert successively a CO ligand to give α-alkoxy chromium acyl complexes, then a tethered triple bond and two additional CO groups to yield bicyclic butenolides.