engleski

Photobehaviour of 2- and 3-heteroaryl substituted o-divinylbenzenes; formation of fused 2,3- and 3,2-heteroareno-benzobicyclo[3.2.1]octadienes and 3-heteroaryl benzobicyclo[2.1.1]hexenes

New beta-3-thienyl (8) and beta-3-furyl derivatives of o-divinylbenzene (9) have been synthesized and their photochemical behaviour compared with 2-thienyl (7) and 2-furyl derivatives (2). Whereas the beta-(2-heteroaryl) substituted o-divinylbenzenes (7 or 2) give only bicyclo[3.2.1]octadiene structure (14 or 1) by 1, 6-ring closure of the biradical intermediate, beta-(3-heteroaryl) substituted o-divinylbenzenes (8 or 9) give bicyclo[3.2.1]octadiene structure (23 or 24) and bicyclo[2.1.1]hexene structure (25 or 26) by 1, 6- and 1, 4-ring closure, respectively. This photochemical approach provides a simple method to 2, 3- and 3, 2-fused thiophene and furan polycyclic compounds.

oxygen heterocycles ; sulfur heterocycles ; furan ; thiophene ; photochemistry ; photocycloaddition ; synthesis

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