Chemical Synthesis of β-<scp>l</scp>-Rhamnose Containing the Pentasaccharide Repeating Unit of the <i>O</i>-Specific Polysaccharide from a Halophilic Bacterium <i>Halomonas ventosae</i> RU5S2EL in the Form of Its 2-Aminoethyl Glycoside
Debasish Pal, Balaram Mukhopadhyay
Abstract
Total synthesis of the pentasaccharide repeating unit of the OPS from Halomonas ventosae RU5S2EL is accomplished through a [3+2] block strategy. Picoloyl-induced hydrogen-bond-assisted aglycon delivery (HAD) is used for two consecutive 1,2-cis-l-rhamnosylations, and remote participation is used for α-selective glucosylation. The choice of 2-aminoethyl glycoside at the reducing end is opted for, leaving the scope for further glycoconjugate formation without hampering the reducing-end stereochemistry.
Topics & Concepts
ChemistryHalophileStereochemistryPolysaccharideGlycoconjugateRhamnoseHalomonasGlycosideBacteriaCombinatorial chemistryBiochemistryGeneticsBiology16S ribosomal RNAGeneCarbohydrate Chemistry and SynthesisLegume Nitrogen Fixing SymbiosisGlycosylation and Glycoproteins Research