Rh2(OAc)4-catalyzed reactions of alpha-diazoimides: a simple and novel synthesis of mono- and bis(2,3-fused perhydrooxazol-4-one) systems.

Simply, trapping the intermediate isomünchnone 1,3-dipoles by the external oxygen nucleophiles resulted in new heterocyclic systems and the use of diols led to the formation of four carbon-oxygen bonds in a single operation which eventually delivered bis(2,3-fused perhydrooxazol-4-one) systems.