Aldulosonic acids

This review summarizes recent approaches towards the selective formation of anomeric aldose and aldulosonic acid phosphates of biological relevance, in particular as precursors for the synthesis of nucleotide-activated sugars. 

Aldulosonic acids are involved in many important areas of glycobiology and glycomedicine, such as /V-acetylneuraminic acid (Neu5Ac), 3-deoxy-D-glycero-v-galacto-non-2- Aosonic acid (Kdn) and 3-deoxy-D-manno-oct-2-ulosonic acid (Kdo). 

Aldulosonic acids can also be prepared by the electro-oxidation of aldosuloses ( osones ) in buffered solutions containing calcium carbonate and bromide further oxidation of the products obtained may occur. Calcium n-archtno-hexulosonate (6) yields calcium D-arabinonate (7) on... 

The selective catalytic oxidation of several 2-ulose derivatives has been studied e.g. the 2,7-anhydroheptulose (265) was selectively oxidized at the axial hydroxy-group to give the corresponding 5-ulose, which rapidly isomerized to the 2,7-anhydrohept-2,4-diulose (266). 2,3-0-Isopropylidene-j8-D-fructopyranose and 2,7-anhydro-4,5-0-isopropylidene-j8-D-a//o-hept-2-ulose were selectively oxidized at HO-4 and HO-3, respectively, whereas the furanose derivative (267) furnished the aldulosonic acid derivative (268). The reduction of these diuloses was also investigated. 

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