AZO BRIDGES FROM AZINES .16. 1,2,3-OXADIAZOLIDINES BY INTRAMOLECULAR [3-CYCLOADDITION(2])

Olefinic bonds and an azoxy group held in a rigid parallel position in systems of type I undergo smooth thermal [3 + 2] cycloadditions which can be strongly catalyzed by acids. Double bonds of a bicycloheptene (norbornene) moiety are ca. 10 times more reactive than those of a bic yclooctene system. The newly formed cage compounds of type K are the f irst stable derivatives of the so far unknown 1,2,3-oxadiazolidine.