Significant Acceleration of 6π-Azaelectrocyclization Resulting from a Remarkable Substituent Effect and Formal Synthesis of the Ocular Age Pigment A2-E by a New Method for Substituted Pyridine Synthesis
by molecular orbital calculations. The formal synthesis of the unusual retinal metabolite, A2-E, was achieved by two types of the new one-pot synthesis of substituted pyridines by utilizing the obtained facile 6 pi-azaelectrocyclization, one of which is compatible with the proposed metabolic pathway of A2-E.