PHOTOCHEMICAL REACTIONS OF 7-AMINOCOUMARINS 1. -CYCLOADDUCTS WITH VINYL BUTYL ETHER AND ACRYLONITRILE

Article abstract of DOI:10.1007/BF00474037

Adducts of <2+2>-cycloaddition to the 3-4 bond were isolated in the photochemical cycloaddition of vinyl butyl ether and acrylonitrile to 4-methyl-7-diethylaminocoumarin.The stereochemical structures of the compounds obtained as isomers of the "head-to-tail" type with an endo or exo orientation of the substituents were established by means of PMR spectroscopy.As a result of an evaluation of the effect of sensitizers and one-electron oxidizing and reducing agents it was found that the investigated reactions proceed through the singlet excited states of 7-aminocoumarins.It is assumed that the regiospecifity of the <2+2>-cycloaddition is determined by the C₍₃₎ reaction center of the coumarin fragment.