209 Pure Appl. Chem., Vol. 77, No. 1, pp. 209–226, 2005. DOI: 10.1351/pac200577010209 © 2005 IUPAC Biocatalytic routes toward pharmaceutically important precursors and novel polymeric systems* Sunil K. Sharma 1,2,3,‡ , Mofazzal Husain 1 , Rajesh Kumar 2,3 , Lynne A. Samuelson 4 , Jayant Kumar 3 , Arthur C. Watterson 2 , and Virinder S. Parmar 1 1 Bioorganic Laboratory, Department of Chemistry, University of Delhi, Delhi 110 007, India; 2 INSET, Department of Chemistry, University of Massachusetts, Lowell, MA 01854, USA; 3 Center for Advanced Materials, Departments of Chemistry and Physics, University of Massachusetts, Lowell, MA 01854, USA; 4 Natick Soldier Center, U.S. Army Soldier and Biological Chemical Command, Kansas Street, Natick, MA 01760, USA Abstract: The synthetic potential of enzymes related to organic synthesis has been applied profusely, especially since the introduction of their use in organic solvents. Enzymes offer the opportunity to carry out highly chemo-, regio-, and enantioselective transformations. The use of enzymes in the synthetic sequence provides unique advantages of efficiency and environ- mental friendliness. Owing to their low cost and applicability to a broad range of substrates, lipases have become the most versatile class of biocatalysts in organic synthesis. We have screened a battery of lipases to carry out highly selective reactions for the synthesis of a wide range of organic compounds and polymeric materials. INTRODUCTION The proper introduction and removal of protecting groups is one of the most important and widely car- ried out synthetic transformations in preparative organic chemistry. In particular, in the highly selective construction of complex, polyfunctional molecules (e.g., oligonucleotides, oligosaccharides, peptides, and conjugates thereof) and in the synthesis of alkaloids, macrolides, polyether antibiotics, prostaglandins, and further natural products, regularly the problem arises that a given functional group has to be protected or deprotected selectively under the mildest conditions and in the presence of func- tionalities of similar reactivity as well as in the presence of structures being sensitive to acids, bases, oxidation, and reduction. Organic chemists have responded to these challenges in a befitting manner, and one of the recent advances in this direction is the application of catalysis as a tool to achieve se- lectivity in organic synthesis. Catalytic organic reactions can be achieved either by chemocatalysis or biocatalysis. Among the important challenges facing organic chemists today is the synthesis of com- pounds in a highly selective and cost-effective manner, utilizing renewable raw materials through envi- ronmentally benign processes. In this endeavor, the synthetic potential of enzymes related to organic synthesis has been applied profusely, especially since the introduction of organic solvent methodology *Paper based on a presentation at the 24 th International Symposium on the Chemistry of Natural Products and the 4 th International Congress on Biodiversity, held jointly in Delhi, India, 26–31 January 2004. Other presentations are published in this issue, pp. 1–344. ‡ Corresponding author