The stereochemistry of 1,2-photocycloaddition of vinylic compounds to benzene

Abstract

The stereochemistry of the 1,2-photocycloaddition of benzene to acrylonitrile, methyl acrylate, methyl methacrylate, methyl vinyl ketone, ethyl vinyl ether, butyl vinyl ether, 2,3-dihydropyran, and 2,3-dihydro-1,4-dioxin has been investigated. The evidence indicates that exo-1,2-adducts are formed exclusively from all these vinylic compounds except the acrylates and methyl vinyl ketone, which gave mixtures of exo- and endo-stereoisomers.