Tricyclic Cephems as Inhibitors of Human Leukocyte Elastase. Thieno(3, 4-c)cepham Sulfones and Pyrrolo(3,4-c)cepham Sulfones.

Abstract Thieno- and pyrrolo[3,4-c]cepham sulfones were synthesized and compared to their furo analogs for activity as human leukocyte elastase inhibitors. Pyrrolo derivatives, especially when N-alkylated, combined excellent hydrolytic stability with remarkable inhibitory activity.