Modification of the cysteamine side chain of thienamycin. II

A new type of thienamycin derivatives (3a-3j, 4a, 4b), having a monothioacetal or a thioacetal side chain at the C-2 position was prepared, and the susceptibility to renal dehydropeptidase-1 (DHP-1) and the antimicrobial activity of these compounds were determined. The structure-activity relationships of these derivatives are also discussed.