Synthesis of the conjugation-ready β-d-rhamnose- and β-d-mannose-containing trisaccharide O-antigen from Serratia spp. strains 10.1WK and 1XS

Abstract

Synthesis of the target trisaccharide O-antigen has been accomplished by following a linear strategy. The challenging 1,2-cis mannoside at the reducing end is prepared from a suitably protected glucoside derivative through inversion of the 2-O-position, leading to the exclusive formation of the β-mannoside moiety. A challenging β-rhamnosidic linkage is achieved by using 3-O-picoloyl-triggered hydrogen-bonding-assisted aglycon delivery. The target trisaccharide in the form of its 2-aminoethyl glycoside is suitable for further conjugation.