Synthesis of spacer-equipped di-, tri-, and the tetrasaccharide fragments of the deacetylated O-PS1 of Citrobacter gillenii O9a,9b, and a related pentasaccharide

were synthesized in a stepwise manner from 5-methoxycarbonylpentyl 4-azido-4,6-dideoxy-2-O-benzyl-α-d-mannopyranoside and orthogonally protected 1-thioglycoside glycosyl donors.