Synthesis of allyl O-[sodium (α-D-glycero-D-talo-2-octulopyranosyl)onate]-2 → 6)-2-acetamido-2-deoxy-β-D-glucopyranoside, a core constituent of the lipopolysaccharide from Acinetobacter calcoaceticus NCTC 10305

Article abstract of DOI:10.1016/0008-6215(93)80005-Y

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 was 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 sodium (methyl β-D-glycero-D-talo-2-octulopyranosid)onate. Alternatively, 2 was transformed into methyl (α-D-glycero-D-talo-2-octulopyranosyl bromide)onate derivatives. Reaction with methanol or allyl 2-acetamido-2-deoxy-3,4-O-(1,1,3,3-tetraisopropyldisiloxan-1,3-diyl)-β -D-glycopyranoside, promoted by silver triflate, gave good yields of the corresponding orthoester derivatives. Me₃Si triflate-catalyzed orthoester rearrangement and removal of the protecting groups afforded sodium O-(methyl α-D-glycero-D-talo-2-octulopyranosid)onate and the disaccharide, allyl O-[sodium (α-D-glycero-D-talo-2-octulopyranosyl)onate]-(2 → 6)-2-acetamido-2-deoxy-β-D-glucopyranoside in high yield. 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 was 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 sodium (methyl β-D-glycero-D-talo-2-octulopyranosid)onate. Alternatively, 2 was transformed into transformed into methyl (α-D-talo-2-octulopyranosyl bromide)onate derivatives. Reaction with methanol or allyl 2-acetamido-2-2-deoxy-3,4-O-(1,1,3, 3-tetraisopropyldisiloxan-1,3-diyl)-β-D-glycopyranoside, promoted by silver triflate, gave good yields of the corresponding orthoester derivatives. Me₃Si triflate-catalyzed orthoester rearrangement and removal of the protecting groups afforded sodium O-(methyl α-D-glycero-D-talo-2-octulopyranosid)onate and the disaccharide, allyl O-[sodium (α-D-talo-2-octulopyranosyl)onate]- (2→6)-2-acetamido-2-deoxy-β-D-glucopyranoside in high yield.