SYNTHESIS OF 3-DEOXYALDULOSONIC ACID-ESTERS BY ONE-CARBON CHAIN EXTENSION OF GLYCAL-DERIVED LACTONE PRECURSORS

A convenient preparative route is described for 3-deoxyaldulosonic aci ds. Glycal precursors are oxidatively converted into 2-deoxyaldonolact ones, which react with 1,3-dithian-2-yl anion to afford 1,3-propanediy l dithioacetals of higher 3-deoxyaldosuloses. Deprotection with mercur ic salts in wet or dry alcohols gave high yields of the corresponding alkyl aldulosonates. Preparative reaction conditions were optimized an d the anomeric configurations of the ketopyranose products were establ ished by C-13 NMR.