Abstract: The potential and limitations of the photochemical ring contraction of 3-diazo-2, 4- pyrrolidinediones as a route to carboxy p-lactams (2-azetidinone-3-carboxylic acids) are explored. Although the method seems to be a fairly general route from a-amino acids to p- lactams, the difficulty of achieving steric control makes the process not especially promising as a route to natural penicillins and cephalosporins. onsiderable ingenuity has been ...
