triol 5 u2032 bases that are suitable for effecting this hydrolysis are known in the art and include potassium carbonate sodium hydroxide potassium hydroxide and the like solvents that are suitable for effecting this hydrolysis are similarly known in the art and include lower alkanols methanol ethanol isopropanol etc advantageously the phenolic primary and secondary hydroxyl moieties of oxazoline triol 5 u2032 may be selectively protected as illustrated below for example the phenolic hydroxyl moiety may be protected as the p nitrobenzoate compound 6 u2032 using p nitrobenzoyl chloride the primary hydroxyl moiety of compound 6 u2032 may then be selectively protected using the same or a different protecting group alternatively both the phenolic and primary hydroxyl moieties of oxazoline triol 5 u2032 may be protected using p nitrobenzoyl chloride to form the di p nitrobenzoate compound 7 u2032 this process may be conducted in a single step using two equivalents of p nitrobenzoyl chloride or in a stepwise process as described above as illustrated in scheme iii treating compound 7 u2032 with methanesulfonyl chloride although another substituted or unsubstituted alkyl or aryl sulfonyl chloride may be used in the presence of a base such as for example triethylamine provided compound 8 u2032 which may be converted into compound 20 u2032 by addition of 3s 4ar 8ar 3 n t butylcarboxamidodecahydroisoquinoline phiq in the presence of potassium carbonate and methanol further treatment with thiophenol provided nelfinavir treatment of compound 7 u2032 with the sulfonyl chloride and base may be conducted using.