The 8-tetracyclo[4.3.0.02,4.03,7]nonyl carbonium ion

✍ Scribed by Peter K. Freeman; Dean M. Balls

• Book ID: 104224103
• Publisher: Elsevier Science
• Year: 1967
• Tongue: French
• Weight: 239 KB
• Volume: 8
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)90965-1

✦ Synopsis

The interesting tetracyclo[4.3.0.02'4.03~7]nonane ring system, which serves as the basic structural unit for the mixture of nitrile epimers (I) obtained in the homo-Diele-Alder condensation of acrylonitrile with norbornadieoe,has not been extensively studied due to the low yields previously encountered in the synthesis of useful inter-" mediates. ' We have developed a facile synthesis of ketone III in two steps: 3 chlorination of the nitriles I (exe and endo) with phosphorus pentachloride in refluxing carbon tetrachloride,4 followed by treatment of chloronitrile II with sodium hydroxide in dimethylsulfoxide gives III in yields of up to 47% based on nitriles I. The structure of tetracyclic ketone III wae confirmed by infrared end n.m.r. spectral comparison with an authentic sample. 5 no.5 An Investigation of the solvolyses of suitable derivatives of Eand ~-8-tetracyclo~~.3.0.0z94.03D7~ _/nonane(IV and V) seemed especially interesting, since, due to the incorporation of both nortricyclene ( carbons 1, 2, 4, 3, 7, 6 and5) andnorbornsne (carbons 1, 2, 3, 7, 8, 9 and6) ring systems into structures IV and V, a double norbornonium ion VIII, as well as the more traditional norbornonium ions VII are possible intermediates.