Synthetic Application of Vinyliminophosphoranes Based on the Reactivity of the Vinyl Side Chain. Preparation of Dihydropyridines

Article abstract of DOI:10.1016/00404-0399(50)1728Z-

New reactions of vinyliminophosphoranes with aldehydes involving an initial nucleophilic attack of the β-carbon atom of the vinyl side chain on the carbonylic carbon atom is reported.The resulting betaines undergo either intra- or intermolecular cyclization to give pyridines or dihydropyridines.