Chemical Synthesis of the Pentasaccharide Related to the Exopolysaccharide of <i>Aeromonas veronii</i> bv. Sobria Strain K49

Total synthesis of the pentasaccharide repeating unit of the exopolysaccharide of <i>Aeromonas veronii</i> bv. sobria strain K49 has been accomplished through a convergent [3 + 2] block synthesis strategy. Rationally designed derivatives of the challenging D-fucosamine and 3-acetamido D-quinovose units have been synthesized through protecting group manipulations and inserted into the target oligosaccharide through stereoselective glycosylations. The number of synthetic intermediates gave nice crystals that helped determine their chemical structures unambiguously.