One-Pot Nonphotochemical Synthesis of Dewar Pyridones from Alkynes and Isocyanates

Article abstract of DOI:10.1021/jo00345a020

A one-pot synthesis of substituted 3-oxo-2-azabicyclo<2.2.0>hex-5-enes (Dewar pyridones) from alkynes, aluminum halides, and isocyanates is described.The mechanism of the reaction of isocyanates with the intermediate aluminum halide ? complexes of cyclobutadienes is discussed on the basis of the substitution pattern of the obtained bicyclic products.The thermal and acid-promoted reactions of some of the compounds are reported.