The synthesis and protonation of mono- and dibenzobisdehydro[15]annulenones. The effect of benzannelation on the diatropicity of a conformationally fixed macrocyclic (4n+2) π-electron system

✍ Scribed by Rex T. Weavers; Richard R. Jones; Franz Sondheimer

• Book ID: 104213987
• Publisher: Elsevier Science
• Year: 1975
• Tongue: French
• Weight: 226 KB
• Volume: 16
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)72640-2

✦ Synopsis

The effect on the ring current of macrocyclic conjugated systems produced by ennelation of one or more benzene rings is of considerable interest. 2 In the 1,3-bisdehydroC14lennulene series, it has been shown that fusion of a benzene ring reduces the diatropicity of the macrocycle, 3 but the interpretation of the data is complicated due to the conformational mobility of the "parent" systems. 4 The bisdehydroC15lannulenone~and the strongly diatropic, confonnationally fixed, protonated species 2 have been prepared previously. 5 We now describe syntheses of the protonated bisdehydroC151 annulenones 2 and 2, formally derived from 2 by -=._.A \