Intramolecular Diels−Alder and Tandem Intramolecular Diels−Alder/1,3-Dipolar Cycloaddition Reactions of 1,3,4-Oxadiazoles

The scope of intramolecular Diels-Alder and a novel tandem Diels-Alder/1,3-dipolar cycloaddition cascade of 1,3,4-oxadiazoles is disclosed. In the cases examined, the tandem cycloadditions construct three new rings with formation of four new C-C bonds and set all six stereocenters about a central six-membered ring in a single step including three contiguous and four total quaternary centers without a trace of a second diastereomer.