Stereoselective Synthesis of α-Keto-deoxy-D-glycero-D-galacto-nonulosonic Acid Glycosides by Means of the 4,5-O-Carbonate Protecting Group

摘要

2-Keto-deoxy-D-glycero-D-galacto-nonulosonic acid (KDN) is a member of the sialic acid family of carbohydrates that are commonly found at the nonreducing terminus of cell surface glycans and in the form of homopolymers. KDN and its glycosides have been long known in marine organisms and have more recently been detected in humans, thanks to improved analytical techniques, opening the way to potential applications as markers of disease states. The minute quantities of these materials available by isolation, and their microheterogeneous nature, points to a strong need for efficient, versatile methods for the synthesis of homogeneous substances by enzymatic or, as described here, chemical methods.