Parallel Solution-Phase Synthesis of Mechanism-Based Cysteine Protease Inhibitors

[reaction--see text] A seven-step parallel solution-phase synthesis has been developed for access to ketone-containing mechanism-based cysteine protease inhibitors. The use of liquid-liquid extractions, volatile or solid-supported reagents, and resin-bound scavengers eliminates the need for intermediate column chromatographic purification during this synthesis sequence.