SYNTHESIS OF ALLYL O-[SODIUM (2-]6)-2-ACETAMIDO-2-DEOXY-BETA-D-GLUCOPYRANOSIDE, A CORE CONSTITUENT OF THE LIPOPOLYSACCHARIDE FROM ACINETOBACTER-CALCOACETICUS NCTC 10305

Reaction of methyl 2,6-anhydro-2,3-dideoxy-D-manno-2-octenoate 1 with 3-chloroperoxybenzoic acid gave the 2,3-anhydro derivative 2, which wa s converted into the per-O-acetylated anomeric methyl glycosides of D- glycero-D-galacto-2-octulopyranosylonic acid in good yield. Subsequent inversion of the configuration at C-3 and deprotection afforded sodiu m (methyl beta-D-glycero-D-talo-2-octulopyranosid)onate. Alternatively , 2 was transformed into methyl (alpha-D-glycero-D-talo-2-oc-tulopyran osyl bromide)onate derivatives. Reaction with methanol or allyl opropy ldisiloxan-1,3-diyl)-beta-D-glycopyranoside, promoted by silver trifla te, gave good yields of the corresponding orthoester derivatives. Me3S i triflate-catalyzed orthoester rearrangement and removal of the prote cting groups afforded sodium O-(methyl alpha-D-glycero-D-talo-2-octulo pyranosid)onate and the disacchanide, allyl O-[sodium lpha-D-glycero-D -talo-2-octulopyranosyl)-onate]-(2 --> 6)-2-acetamido-2-deoxy-beta-D-g lucopyranoside in high yield.