Abstract: Photolysis of chromium alkoxycarbene complexes with N-(benzy1oxycarbonyl) imidazolines produced protected azapenams. Hydrogenolysis gave free azapenams which were stable, one of which was characterized by X-ray crystallography. Hydrogenolysis under acidic conditions produced hexahydro-l, 4-diazepin-5-ones. Treatment of the free azapenams with camphorsulfonic acid produced unsaturated 14-membered ...
[Kuhn, Kevin M.; Bourg, Jean-Baptiste; Chung, Cheol K.; Virgil, Scott C.; Grubbs, Robert H. Journal of the American Chemical Society, 2009 , vol. 131, p. 5313 - 5320]