An Expedient Construction of Seven-Membered Rings Adjoining Aromatic Systems

✍ Scribed by Talbi Kaoudi; Béatrice Quiclet-Sire; Stéphanie Seguin; Samir Z. Zard

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 87 KB
• Volume: 112
• Category: Article
• ISSN: 0044-8249
• DOI: 10.1002/(sici)1521-3757(20000218)112:4<747::aid-ange747>3.0.co;2-w

✦ Synopsis

In contrast to the closure of five-and six-membered rings, the direct formation of a seven-membered ring by radical addition to an olefin is a relatively uncommon transformation. [1,2] Examples of the even more difficult corresponding cyclization onto an aromatic ring are very rare. [3] Yet, sevenmembered rings adjoining aromatic systems can be found in a variety of biologically active compounds, for example, clavicipitic acid (1), a metabolite related to lysergic acid, [4] the more complex, recently isolated welwitindolinones (e.g. Nmethylwelwitindolinone C isothiocyanate (2)), [5] and the benzazepine family of drugs [6] such as Zatebradine (3), an antianginal and one of a new group of specific bradycardic agents. [6c,d]