An unprecedented Co-II-tetraphenylporphyrin-catalyzed decomposition of bicyclic endoperoxides: A new approach to substituted furofuran systems

Co-II-tetraphenylporphyrin-catalyzed decomposition of bicyclic endoperoxide s 4 and 5 with a strained double bond moiety has been studied. Compounds 4 and 5 have been synthesized by photooxygenation of 3 which itself was obtai ned by dichloroketene addition to cycloheptatriene, followed by removal of the chlorine atoms. An unusual decomposition mode of 4 promoted by Co-II-TP P resulted in the formation of 8 and 9 which are important building blocks in furofuran systems.