Steady-State and Laser Flash Photolysis Studies of 1-Aziridinyl-1,2-dibenzoylalkenes

Article abstract of DOI:10.1021/jo00222a022

Results of a photochemical study based on product analysis and 337.1-nm laser flash photolysis are reported for several cis- and trans-1,2-dibenzoylethylenes bearing aziridinyl groups at the 1-position.Products isolated from steady-state photolysis suggest facile ring expansion yielding pyrrolines as well as extrusion of alkenes from the aziridine moieties forming nitrene fragments, which subsequently undergo ring closure to give isoxazoles.Laser flash photolysis studies show transient absorption changes, explainable in terms of cis-trans photoisomerisation and formation of azomethine ylides.The latter are also observed upon steady-state irradiation of these aziridinyl-1,2-dibenzoylethylenes in an EPA glass at 77 K.