Syntheses and properties of methano-bridged dichlorodidehydro-[16]-, -[20]-and-[24]-annulenediones
摘要:
Bisethynylation of the vinylogous dialdehydes of cyclohepta-1.3,5-triene-1,6-dicarbaldehyde with ethynylmagnesium bromide followed by oxidation of the resulted diols afforded the diacetylenic diketones. Intramolecular oxidative coupling of these diketones under the Glaser conditions unexpectedly afforded three annulenediones with a 1,4-dichlorobutatriene moiety. The unusual structures were confirmed by X-ray crystallographic analysis of 10,13-dichloro-11.12-didehydro-1,6methano[16]annulene-9,1 4-dione. These annulenediones exhibited strong diatropicity in D2SO4 due to the dicationic 14 pi-, 18 pi- and 22 pi-electron species and their diatropicities were shown to increase with increasing ring size.
Syntheses and properties of methano-bridged dichlorodidehydro-[16]-, -[20]-and-[24]-annulenediones
摘要:
Bisethynylation of the vinylogous dialdehydes of cyclohepta-1.3,5-triene-1,6-dicarbaldehyde with ethynylmagnesium bromide followed by oxidation of the resulted diols afforded the diacetylenic diketones. Intramolecular oxidative coupling of these diketones under the Glaser conditions unexpectedly afforded three annulenediones with a 1,4-dichlorobutatriene moiety. The unusual structures were confirmed by X-ray crystallographic analysis of 10,13-dichloro-11.12-didehydro-1,6methano[16]annulene-9,1 4-dione. These annulenediones exhibited strong diatropicity in D2SO4 due to the dicationic 14 pi-, 18 pi- and 22 pi-electron species and their diatropicities were shown to increase with increasing ring size.
Bisethynylation of the vinylogous dialdehydes of cyclohepta-1.3,5-triene-1,6-dicarbaldehyde with ethynylmagnesium bromide followed by oxidation of the resulted diols afforded the diacetylenic diketones. Intramolecular oxidative coupling of these diketones under the Glaser conditions unexpectedly afforded three annulenediones with a 1,4-dichlorobutatriene moiety. The unusual structures were confirmed by X-ray crystallographic analysis of 10,13-dichloro-11.12-didehydro-1,6methano[16]annulene-9,1 4-dione. These annulenediones exhibited strong diatropicity in D2SO4 due to the dicationic 14 pi-, 18 pi- and 22 pi-electron species and their diatropicities were shown to increase with increasing ring size.