Leucine-phenylalanine dipeptide-based N-mesyloxysuccinimides: synthesis of all four stereoisomers and their assay against serine proteases.

The four stereoisomers of 3-(N-acetylleucylamino)-3-benzyl-1-[(methylsulfonyl)oxy]succinimide have been prepared and shown to inhibit α-chymotrypsin and human neutrophil elastase. The structural and stereochemical features that affect the potency and selectivity of inhibition are discussed.