title: Reactions involving di-trans-[12]annulenes.
abstract: The low temperature complete dehydrohalogenation of pentabromocyclododecene (C12H17Br5) with potassium tert-butoxide in THF followed by exposure to potassium metal leads to the formation of the anion radical of 1,5-di-trans-[12]annulene, which loses hydrogen and undergoes ring closure to form the anion radical of 11,12-dihydro-[8]annuleno-[6]annulene. This product can, in turn, be isolated as its neutral molecule via reoxidation with iodine. A [12]annulene obtained via the dimerization of 1,5-hexadiyne in the presence of 18-crown-6 and potassium tert-butoxide undergoes ring closure, with concomitant loss of hydrogen, to yield the heptalene anion radical. It follows that the heptalene anion radical precursor was the 1,7-di-trans isomer of [12]annulene.
authors.affiliation: Department of Chemistry, Illinois State University, Normal, Illinois 61790-4160, USA.
authors.forename: Matthew K
authors.initials: MK
authors.lastname: Kiesewetter
authors.forename: Matthew N
authors.initials: MN
authors.lastname: Gard
authors.forename: Richard C
authors.initials: RC
authors.lastname: Reiter
authors.forename: Cheryl D
authors.initials: CD
authors.lastname: Stevenson