Cycloaddition of dienes to nitroso- and azo-alkenes

Abstract

Furan, 2,5-dimethylfuran, and cyclopentadiene add to the nitroso- and azo-alkenes (1) and (2) to give the oxazine and pyridazine derivatives (3) and (4); a mechanism involving Diels-Alder addition followed by rapid [3,3] rearrangement is proposed.