Asymmetric total synthesis of erythromycin. 3. Total synthesis of erythromycin

In the preceding paper' we described the preparation of the lactone intermediate la in optically active form. In this paper we report the synthesis of erythromycin (2) from la. In essence,this transformation involves the glycosidation of a suitable derivative of la with L-cladinose and D-desosamine and the generation of the C-9 ketone functionality.