Reactions of (E)-1,2-di(3-guaiazulenyl)ethylene and 2-(3-guaiazulenyl)-1,1-bis(4-methoxyphenyl)ethylene with tetracyanoethylene (TCNE) in benzene: comparative studies on the products and their spectroscopic properties

Reactions of the title ethylene derivatives 1 and 2 with TCNE in benzene at 25 °C for 24 h under argon give new cycloaddition compounds 3 (from 1) and 4 (from 2), respectively, in 66 and 87% isolated yields. Comparative studies on the above reactions as well as the spectroscopic properties of the unique products 3 and 4, possessing interesting molecular structures, are reported.