Scheme A ln order to obtain a repetitive process of the three steps, activation, cyclization, and aminolysis, for each 0 (-arninosulfonic acid to be incorporated for lengthening the pseudopeptide chain Y, A'must be equivalent to A, z'. e. Z must be selected to insure aminolysis with cleavage (a) of the cyclic compound B. Hence, we have undertaken the study of different cases (Scheme A).
