The reaction of benz(de)anthracenyl anion with methylene chloride/n-butyllithium

✍ Scribed by Richard M. Pagni; Michael Burnett; Alan C. Hazell

• Publisher: Elsevier Science
• Year: 1977
• Tongue: French
• Weight: 205 KB
• Volume: 18
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)92577-8

✦ Synopsis

The addition of chlorocarbenel to cyclic v anions has become a reaction of synthetic utility in recent years.2-5 Perhaps the best known reaction of this type is Katz's preparation of benzvalene from the addition of chlorocarbene to the cyclopentadienyl anion (L).2 In all of the anions which have been studied (1 through A), the addition of the carbene appears to be completely regiospecific either because of the high intrinsic symmetry of anion (_1,2 2,3 and A4), where only one site of attack is possible, or, when the anion lacks high symmetry as with L2 and z5, attack on the benzene ring is precluded because aromaticity would be destroyed in the process.6 We decided to investigate the reaction of chlorocarbene with hanz(de)anthracenyl anion (k), because of the expectation that more than one site of this unsymmetrical anion might be attacked by chlorocarbene. This expectation was realized.