[Synthesis of 2-acrylamidoethylglycosides of 3-O-(beta-D- glucopyranosyluronic acid)-alpha-L-rhamnose and 3-O-(alpha-L- rhamnopyranosyl)-beta-D-glucopyranuronic acid and copolymeric artificial antigens based on them].

The synthesis of disaccharide repeating units, D-GlcA-(beta 1----3)-L-Rha (fragment A) and L-Rha-(alpha 1----3)-D-GlcA (fragment B), of the K54-antigenic polysaccharide from uropathogenic Escherichia coli 06:K54:H10 is described. Essential stages of the synthesis of fragment A involved the glycosylation of methyl 2,4-di-O-benzoyl-alpha-L-rhamnopyranoside followed by acetolysis of the methyl bioside obtained and further transformation into 2-(benzyloxycarbonylamino)ethyl glycoside; deprotection and, finally, conversion into 2-(acrylamido)ethyl glycoside. Selective opening of lactone ring in 2-azidoethyl 2,4-di-O-acetyl-beta-D-glucopyranoside-6,3-lactone was used for deprotection of 3-OH group in the synthesis of fragment B. Rhamnosylation of the glucuronic acid derivative thus obtained followed by transformation into 2-(acrylamido)ethyl glycoside and deprotection gave fragment B. Both fragments A and B were converted into artificial antigens of copolymer type.