The Synthesis of Carbapenem and Carbacephem Derivatives by a Combination of 4CC with the Chemistry of Oxazoles and N-boc-carbonamides

A synthetic approach to carhapenem and carhacephem derivatives is described.It is based on the formation of the N-carboxyaethyl-8-lactao system by a four component condensation, the cleavage of s carhonaaide via the N-Boc-carbonasides and esters, and the masking of a carboxyl group as its 4.5-diphenylaxazolyl derivative that is convertible to an N,N-dihenzoylamide by photooxidation.With very few exceptions, the substructure 1 is the characteristic common feature of the 0-lactam antibiotics, one of the favored research topics of Kametani et al.' In some of the most effective synthetic approaches to the b-lactam antibiotics, the key step is a four component condensation (4CC.Ugi reacti~n),~ 2 + 3 + 4 -) 5. 2 3 4 5 In the present paper re describe a 4CC based synthetic route that may aerve for the preparation of a variety of carbapenems and carbacephems t3 a (R= Me) u b @ dfl)