4-Hydroxy-13,13-dimethyl-9-(1-methylethyl)-8,11-dioxo-3,6-bis(phenylmethyl) 12-Oxa-2,7,10-triazatetradecanoic Acid 5-Thiazolylmethyl Ester, is an intermediate that can be used for the synthesis of Ritonavir (R535000), which is a selective HIV protease inhibitor.