Gas-phase pyrolytic formation and dimerization of benzocyclobutenes: Synthesis of [2(4)](1,2,4,5) cyclophane.
Gas-phase pyrolysis of benzocyclobutenes in a nitrogen stream at 450 degrees C is a convenient efficient method for preparing dibenzocyclooctadienes. Application of this method to benzo[1,2;4,5]dicyclobutene gives [2(4)](1,2,4,5)cyclophane directly. However, under the same reaction conditions, 3,6-dimethylbenzo[1,2;4,5]dicyclobutene gives the open [2.2]orthocyclophane derivative, whose structure has been established by x-ray crystallographic analysis of the corresponding iron complex.
Department of Chemistry, University of Oregon, Eugene, Oregon 97403.
B E
BE
Eaton
E D
ED
Laganis
V
V
Boekelheide