Synthesis of the novel conjugated ω,ω′-diaryl/heteroaryl hexatriene system with the central double bond in a heteroaromatic ring: photochemical transformations of 2,3-divinylfuran derivatives

Abstract: New β,β′-aryl/heteroaryl 2,3-divinylfuran derivatives (9a–d) in which a hexatriene system is a part of heteroaromatic ring have been synthesized and their photochemical properties were investigated. The primary process observed was the isomerization to trans,trans-isomers 9a–d followed by photochemical rearrangement of the furan ring giving the phototransposition products (I–IV). Stilbenes (20, 21) and phenanthrenes (22, 25, and 26), formed as secondary products from the competitive intermolecular cycloadditions, were also observed. [Copyright &y& Elsevier]