Bulletin of the Chemical Society of Japan · 1976 · 16 citations · 6 references
Natural SciencesChemistryBioorganic ChemistryOrganic ChemistrySynthetic Medicinal ChemistryHeterocycle SynthesisHeterocyclic ChemistryOrganic SynthesisRetrosynthetic AnalysisAnnulation ReactionsOxidative CouplingOxidative Coupling ReactionsRing-forming ReactionsWittig Reaction
Abstract In order to establish the effect of the annelation of benzene rings on [4n+2] annulenes, the syntheses of benzannelated dehydroannulenes were attempted. Dibenzo-tetrakisdehydro[ 18]annulenes (IIa and IIb) were prepared according to the reaction sequence developed in the synthesis of tetramethyltetrakisdehydro[18]annulene (I) from o-ethynylbenzaldehyde (VIII); both of them proved to be unstable. Tribenzo-bisdehydro[14]annulene (XVII) was also prepared from VIII by a double Wittig reaction, followed by oxidative coupling. An examination of the NMR spectrum indicated that XVII is atropic.
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