Cycloaddition studies directed toward the strychnos alkaloid minfiensine

The thermolysis of several imidofuranyl carbamates delivers products derived from an intramolecular [4+2]-cycloaddition reaction. In the case of the ortho-azido aryl carbamate 13, the preferred path proceeds by an electrocyclization of a nitrene intermediate to produce a 3-substituted indole. Attempts to reduce the azido group resulted in a novel intramolecular aza-Wittig reaction with the neighboring imido group.