engleski

Photoreactions of mono- and disubstituted conjugated furan derivatives

We have been using photochemical methodology in the synthesis of furan polycyclic structures, potentially biologically active compounds. The irradiation of the unsubstituted furan derivative 1 results in intramolecular [2+2] photocycloaddition and formation of the bicyclo[3.2.1]octadiene structure 2 in a very good yield. The 3-substituted furan derivatives 1 give upon irradiation bicyclo[2.1.1]hexene structure 3. The diheteroaryl substituted o-divinylbenzenes 4 give bicyclo[3.2.1]octadiene structure 2, as a result of intramolecular cycloaddition reaction, besides intermolecular photoproducts, cyclophanes and cyclobutanes. Contrary to these results, 2, 3-distyrylfurans 5 give only phototransposition products. No intramolecular cycloaddition has been observed. The identification and the mechanism of the formatiobn of the obtained products products will be discussed.

furans; photoreactions; polycyclic structures; photocycloaddition; o-divinylbenzenes; bicyckic structures; cyclophanes; phototransposition products

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