Chemical and Chemo-Enzymatic Approaches to Unnatural Ketoses and Glycosidase Inhibitors with Basic Nitrogen in the Sugar Ring

Abstract

Abstract: The intramolecular reductive amination of the carbonyl group in a y- or 8-aminoaldose or -ketose was employed as the first synthetic access to iminoalditols. Over the past thirty years, this approach has remained one of the most important methods for the synthesis of highly functionalized monocyclic as well as bicyclic alkaloidal carbohydrate mimics from sugars. Such compounds have been found to exhibit exciting biological properties. Because aminoaldehydes and aminoketones are key intermediates, preparative approaches to these compounds have been devised based on a variety of chemical as well as enzymatic methods. These include the chemical synthesis as well as the modification of sugars and the enzymatic construction of the carbon backbone from suitably functionalized precursors. Recently, chemical as well as enzymatic isomerization reactions of modified mono- and disaccharides have been identified as viable alternatives to these established strategies.