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. Other 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.