Recent progress in polymer-supported synthesis of oligosaccharides and carbohydrate libraries

Glycobiology is a rapidly evolving field and tackles many phenomena of biom edical importance. Driven by the need to create more efficient methods for the synthesis of complex oligosaccharides, the last few years have seen a m ajor push toward a general approach amenable to solid-phase synthesis. Diff erent strategies have been explored and a host of glycosylating agents have been investigated. New linker systems, different solid support materials a nd a variety of protective groups have been evaluated. The development of o n-resin analytical techniques such as MAS-NMR have greatly facilitated the development of new methods for solid-phase oligosaccharide synthesis. These methodological advances have been demonstrated by preparation of several c omplex oligosaccharides. As the coupling yields have been improved to 95% a nd above, the desired products could be obtained in good yield even after s even glycosylations. In addition to single target structures, carbohydrates have generated rapid ly increasing interest with respect to sets of diverse, carbohydrate contai ning molecules. These efforts are of increasing importance for providing mo lecular tools to elucidate biological processes. While much has been achieved to date, the difficulties encountered in the s olid-phase assembly of oligosaccharides underscore the need for the develop ments of all facets of carbohydrate chemistry. Given the rapid progress in the past eight years, it is conceivable that the synthesis of 'simple' olig osaccharides may soon be automated. Careful investigations into many parame ters will eventually allow the synthetic chemist to enable even non-special ists to create important tools for biochemical, biophysical, and medical ap plications.