1,2-Dihydropentalenes from Fulvenes by [6+2] Cycloadditions with 1-Isopropenylpyrrolidine

Coskun N. , Ma J., Azimi S., Gaertner C., Erden I.

ORGANIC LETTERS, vol.13, no.22, pp.5952-5955, 2011 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 13 Issue: 22
  • Publication Date: 2011
  • Doi Number: 10.1021/ol202222d
  • Title of Journal : ORGANIC LETTERS
  • Page Numbers: pp.5952-5955


In situ generated acetone pyrrolidine enamine undergoes [6 + 2] cycloadditions with fulvenes to give 1,2-dihydropentalenes. This ring annulation method works particularly well with 6-monosubstituted fulvenes and is subject to steric hindrance at C-6 of the fulvene. On the basis of mechanistic studies, optimal conditions have been developed for a one-pot synthesis of 1,2-dihydropentalenes using catalytic amounts of pyrrolidine.