A new Kdo derivative for the synthesis of an inner-core disaccharide of lipopolysaccharides and lopooligosaccharides

Methyl (7,8-di-O-benzoyl-4,5-O-isopropylidene-3-deoxy-d-manno-2-oct-ulopyranoside)onate was found to be a useful new intermediate in the synthesis of an inner-core oligosaccharide of lipooligosaccharides and lipopolysaccharides produced by gram-negative bacteria. This intermediate could be converted to the corresponding glycosyl fluoride and 4,5-diol acceptor with ease. Syntheses of dimeric Kdo, O-(sodium 3-deoxy-α-d-manno-2-octuropyranosylonate)-(2–4)-sodium (allyl 3-deoxy-α-d-manno-2-octuropyranoside)onate, and O-(sodium 3-deoxy-α-d-manno-2-octuropyranosylonate)-(2–8)-sodium (allyl 3-deoxy-α-d-manno-2-octuropyranoside)onate were successfully demonstrated.