Septulene: The Heptagonal Homologue of Kekulene


  • This work was supported by the US-NSF (CHE-0957702). We thank Dr. S. M. Spain and Dr. J. L. Dallas (NSF DBI-0722538) for assistance with spectroscopy, and Profs. A. D. Schlüter, K. K. Baldridge, and H. B. Bürgi for useful suggestions.


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A family likeness: The seven-sided homologue of kekulene, septulene (see structure), has been synthesized in seven steps by ring-closing metathesis. Its properties (spectroscopic and structural) are strikingly similar to those of kekulene despite its sevenfold symmetry and resulting non-alternant structure. The chair-type conformation in the crystal arises from packing forces. Septulene is probably a free pseudorotor in the gas phase.