Cylindradines A and B, members of the polycyclic pyrrole-imidazole alkaloids (PIAs), are the only congeners bearing a 3-carbamoylpyrrole unit among the PIAs. In this communication, we described a total synthesis of (+)-cylindradine A based on intramolecular Friedel-Crafts type cyclization of pyrrole-aldehyde and oxidative cyclization of tricyclic pyrrolopyrrolidine-guanidine with hypervalent iodine to construct the cyclic guanidine structure including the N,N'-aminal moiety.

Total Synthesis of (+)-Cylindradine A (I). -(IWATA, M.; KANOH, K.; IMAOKA, T.; NAGASAWA*, K.; Chem. Commun. (Cambridge) 50 (2014) 53, 6991-6994, http://dx.doi.org/10.1039/c4cc00137k ; Dep. Biotechnol. Life Sci., Tokyo Univ. Agric. Technol., Koganei, Tokyo 184, Japan; Eng.) -M. Paetzel 48-202