Struktur und Reaktivität von isoanellierten heterocyclischen Systemen mit 4nπ- und (4n+2)π-Elektronen, XIV [1]: Tri- und tetracyclische Hetarene mit lokalisierten oder delokalisierten PyrroI-Strukturen / Structure and Reactivity of Isoannellated Heterocyclic Systems with 4nπ- and (4n+2)π-Electrons, XIV [1]: Tri- and Tetracyclic Hetarenes with Localized or Delocalized Pyrrole Units

Abstract

Abstract 2,7-Di-tert-butyl-2,7-dihydro-benzo[ 1,2-c:3,4-c′]dipyrrole (2b) and 2,5,8-Tri-tert-butyl-5.8-di-hydro-2H-benzo[1,2-c:3,4-c′:5,6-c″]tripyrrole (3b) have been prepared by acetolysis of the cor-responding tri-and tetracyclic N-oxides, isolated in crystallinic form and characterized by spectroscopic data. The scope of the N-oxide route is documented and the existence of benzoannellated pyrroles is proofed. The stabilizing effect of the tert-butyl group is presumably sup-ported by the vicinal annellated heterocycles.