Total Synthesis of Conjugation-Ready Tetrasaccharide Repeating Units of a Multidrug-Resistant Pathogen Acinetobacter baumannii Strain 34 and O5

Abstract

Herein, we report the first total synthesis of conjugation-ready tetrasaccharide repeating units of Acinetobacter baumannii strain 34 and O5 comprising a common disaccharide motif [α-L-FucpNAc-(1→4)-α-D-GalpNAcA]. The installation of 1,2-cis linkages employing a disarmed 2-azido-D-galacturonic acid derivative as the donor is addressed here. The synthesis of the tetrasaccharide repeating units of A. baumannii strain 34 and O5 is accomplished via the longest linear sequences of 19 steps in 9.8% and 21 steps in 8.4% overall yields, respectively.

Stereoselective α‐Glycosylation with GlcN3 Donors Enabled Collective Syntheses of Acinetobacter baumannii Capsular Polysaccharides K43, K47 and K88 Repeating Units†

“…Different from traditional and stepwise carbohydrates synthesis, [ 9‐10 ] one‐pot assembly of glycans not only avoids the work‐ups and time‐consuming purification of the intermediates, but also accelerates the synthesis and reduces the chemical wastes, thus highly streamlining carbohydrates synthesis. [ 11‐12 ] Herein, we report collective syntheses of A. baumannii CPS K43, K47 and K88 repeating units 1 — 3 via an orthogonal one‐pot coupling strategy on the basis of glycosyl ortho ‐(1‐phenylvinyl)benzoates (PVB).…”

Total Synthesis of Vibrio Cholerae O43 Tetrasaccharide Repeating Unit

“…For the procurement of rare monosaccharide building blocks, we have used our established protocol via one-pot S N 2 displacement of 2,4-bis-triflates derived from commercially available d -mannose. , The efficiency of the protocol is well-demonstrated with the access to various d / l -bacterial rare sugars, which enabled total synthesis of important and structurally complex bacterial glycoconjugates. − Recently, we reported a brief communication on the first total synthesis of V. cholerae O43 tetrasaccharide RU . In this paper, we present a detailed report of our in-depth studies directed toward the synthesis of the target tetrasaccharide via stereoselective assembly of rare sugar building blocks, late-stage amide coupling, and oxidation.…”