Naslov
Studies in the cycloproparene series: chemistry of 1H-cyclopropa[b]naphthalene-3,6-dione and its transformation into 1H-cyclopropa[b]anthracene-3,8-dione

Autori
Halton, Brian ; Jones, Carissa, S. ; Kay, Andrew, J. ; Margetić, Davor ; Sretenović, Sanja

Izvornik
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 1 (1470-4358) 14 (2000); 2205-2210

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Radovi u časopisima, članak, znanstveni

Ključne riječi
CYCLOADDITION REACTIONS; NAPHTHO<B>CYCLOPROPENE; BENZOCYCLOPROPENE; 1;3-DIPHENYLISOBENZOFURAN

Sažetak
1H-Cyclopropa[b]naphthalene-3,6-dione 3 adds bromine stoichiometrically across the enedione C=C bond to give dibromodihydrocyclopropanaphthalenedione 10 while with an excess of the reagent (bromomethyl)tribromonaphthoquinone 12 is formed. Typical quinone character is exhibited by 3 in Diels-Alder cycloadditions and it gives the endo-methanocyclopropanthraquinone 14 with cyclopentadiene. With buta-1,3-diene the analogous tetrahydrocyclopropanthraquinone 15 is formed from a temperature dependent reaction. Above 45 degrees C opening of the three-membered ring of 4 also occurs and the cyclopentanthracenedione 16 is obtained from [pi 2+pi 4] and [sigma 2+pi 2] additions; it is the sole product at 100 degrees C. Enolisation of the tetrahydroanthraquinone 15 provides diphenolate 18 and this can be diverted to diether 19 or readily oxidized to the dihydroanthraquinone 20. In turn, 20 is dehydrogenated to the fully aromatic cyclopropa[b]anthracene-3,8-dione 4, the first anthraquinone of the cycloproparene series.

Izvorni jezik
Engleski

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