title: A Cyclopropabenzenylidenethenone (propadienone) via a new route to alkylidenecycloproparenes.
abstract: Reaction of 1,1-dichloro-2,5-diphenylcyclopropabenzene 6 with Meldrum's acid 8 in the presence of pyridine leads to coupling of the cycloproparenyl cation 7 with the stabilized diketo anion 9. Subsequent, spontaneous, base-induced dehydrochlorination gives the alkylidenecyclopropabenzene 11 in a one-pot reaction. Flash vacuum thermolysis of 11 at 650 degrees C ejects acetone and carbon dioxide, giving cyclopropabenzenylidenethenone 12 that is isolated in an Ar matrix at 20 K and characterized by a strong ketene band at 2107 cm(-1) in the IR spectrum. [reaction: see text]
authors.affiliation: School of Chemical & Physical Sciences, Victoria University of Wellington, P.O. Box 600, Wellington, New Zealand. brian.halton@vuw.ac.nz
authors.forename: Brian
authors.initials: B
authors.lastname: Halton
authors.forename: Gareth M
authors.initials: GM
authors.lastname: Dixon
authors.forename: Carissa S
authors.initials: CS
authors.lastname: Jones
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Parkin
authors.forename: Rakesh N
authors.initials: RN
authors.lastname: Veedu
authors.forename: Holger
authors.initials: H
authors.lastname: Bornemann
authors.forename: Curt
authors.initials: C
authors.lastname: Wentrup