text: Oxanorbornadiene (or another activated alkene) reacts with azides, giving triazoles as a product. However, these product triazoles are not aromatic as they are in the CuAAC or SPAAC reactions, and as a result are not as stable. The activated double bond in oxanobornadiene makes a triazoline intermediate that subsequently spontaneously undergoes a retro Diels-alder reaction to release furan and give 1,2,3- or 1,4,5-triazoles. Even though this reaction is slow, it is useful because oxabornodiene is relatively simple to synthesize. The reaction is not, however, entirely chemoselective.