Reactive adhesive compositions that can be activated with actinic radiation, manipulated for an extended time and then cured thermally are disclosed. The prepolymer mixture for the reactive adhesive contains a catalyst component and a monomer/oligomer component. The monomer or oligomer is chosen from oxetane monomers, oxirane monomers, oxetane oligomers and oxirane oligomers. The oxirane monomers and oligomers have at least one oxygen or sulfur of an ether or thioether in a position two or three carbons removed from the oxygen of the oxirane.