A synthesis of 3-O-(2-Acetamido-2-deoxy-α-D-galactopyranosyl)-D-galactopyranose and 3-O-α-D-Galactopyranosyl-D-galactopyranose

Abstract

The condensation of 1,2:5,6-di-O-isopropylidene-α-D-galactose with dimeric tri-O-acetyl-2-deoxy-2-nitroso-α-D-galactopyranosyl chloride gives 3-O-(tri-O-acetyl-2-hydroxyimino-α-D-lyxo-hexopyranosyl)-1,2:5,6- di-O-isopropylidene-α-D-galactose. This hydroxyimino glycoside may then be converted, by an established reductive sequence, into the title 2- acetamido-2-deoxydisaccharide and its talo epimer. Alternatively, hydrolysis of the hydroxyimino glycoside yields a ketone which, again by an established reductive sequence, may be converted into the title disaccharide and its talo epimer.