Photochemical [2+2] cycloaddition reaction of enone derivatives with 2-siloxy-1H-pyrrole derivatives

Abstract

The regio- and stereo-selectivity of the photochemical [2+2] cycloaddition reaction of 2-(t-butyldimethylsilyloxy)-1H-pyrrole with enone derivatives are investigated. Regioselective formation of cyclobutanes was found in the intermolecular photochemical [2+2] cycloaddition reaction of the pyrrole derivative with cyclopentenone. In contrast, an oxetane rather than a cyclobutane product was selectively formed when 1,4-naphthoquinone was used as the enone. The reaction conditions were optimized to obtain the cycloadducts in high yields.