A Process in Need Is a Process Indeed: Scalable Enantioselective Synthesis of Chiral Compounds for the Pharmaceutical Industry

This report deals with enantioselective synthesis of viracept 1 (nelfinavir mesylate, AG 1343), a potent HIV protease inhibitor, and 3-hydroxytetradecanoic acid 3, a component of lipid A comprising lipopolysaccharide embedded in the cell surface of Gram-negative bacteria, from both strategic and practical perspectives. As regards the synthesis of 1, the synthetic approaches to its central intermediate 2 possessing the common structural motif of 1,4-differentially substituted-2-amino-3-hydroxylbutane are mainly discussed with emphasis on the molecular symmetry that has helped streamline the synthetic strategy. In the discussion of the synthetic strategies to access a single enantiomer of 3, the chiral methodologies that have been applied so far are assessed for industrial viability; the synthetic alternatives explored include resolution via diastereomeric salt formation, lipase-catalyzed kinetic resolution, asymmetric synthesis, and chiral pool approaches.