Benzyl ((2R,3R)-4-Chloro-3-hydroxy-1-(phenylsulfonyl)butan-2-yl)carbamate is derived from (2R,3R)-1-Chloro-2-hydroxy-3-[(benzyloxycarbonyl)amino]-4-(phenylthio)butane (C367765), which is used in the preparation of HIV protease inhibitor streptolysin.