engleski

Photochemical Behaviour of o-Stilbenyl-Pyrroles and Sydnones

Heterocyclic stilbene analogues, furan, benzofuran, naphthofuran as well as pyrrole derivatives of o-divinylbenzene (1), are useful substrates for the photochemical transformations to heteropolicyclic compounds in one step. While furan and benzofuran derivatives give bicyclo[3.2.1]octadiene structures by intramolecular cycloaddition and heterocyclic ring participation, the naphthofuran analogues give cyclobutane products, formed by [2+2] intermolecular cycloaddition. Nitrogen analogues, with pyrrole ring as a substituent behave completely different, giving dimeric products by intermolecular pyrrole addition to the double bond. In order to prepare heteropolycyclic compounds with one or two nitrogen atoms using photochemical methodology, new stilbene derivatives 2 and 3 were synthesised and photolysed. The identification of intra- and intermolecular products as well as the reaction mechanism will be discussed.

photochemistry; pyrroles; sydnones; stilbenes; intramolecular cycloaddition

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