A Facile Synthesis of Tetra- and Dihydronaphthalene Derivatives by Excimer Laser Photolysis of 1,2-Bis(substituted-methyl)benzenes in the Presence of Olefins and Acetylene.

Abstract

o-Quinodimethane (3A) was generated effectively by excimer laser photolyses of 1,2-bis(phenoxymethyl)benzene (1-O), 1,2-bis[(phenylthio)methyl]benzene (1-S), and 1,2-bis[(phenylseleno)methyl]benzene (1-Se) in acetonitrile solutions via a two-photon process, which was followed by cycloaddition of 3A with several dienophiles-maleic anhydride (4a), dimethyl maleate (4b), dimethyl fumarate (4c), fumaronitrile (4d), and dimethyl acetylenedicarboxylate (4e)-to give corresponding cycloadducts 5. Three kinds of excimer lasers, namely, KrF (248 nm), XeCl (308 nm), and XeF (351 nm) excimer lasers were used for the reaction. The KrF excimer laser was found to be most effective for obtaining high consumption of 1-(O, S, Se) and yield of 5; the maximum yield of the cycloadduct obtained was 48%.