1,3-Dipolar Cycloaddition of 1-Phenylpropa-1,2-diene with Pyridinium Dicyanomethylides: 1-Phenylpropa-1,2-diene as a Synthetic Equivalent of 1-Phenylpropyne

Abstract

Pyridinium dicyanomethylides (1) underwent 1, 3-dipolar cycloaddition with 1-phenyl-propa-1,2-diene (2) to give a mixture of 3-cyano-2-methyl-1phenylindolizines (4) and 3-cyano-1-methyl-2-phenylindolizines (5), accompanied by dehydrocyanation and 1, 3-sigmatropic hydrogen shift.Pyridinium dicyanomethylides (1) and pyridinium bis(methoxycarbonyl)methylides are of synthetic