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

The title rhamnooligosaccharides [α-d-Rhap4NAc-(1→3)-α-d-Rhap4NAc-1-O-(CH2)5COOMe, α-d-Rhap4NAc-(1→3)-α-d-Rhap4NAc-(1→3)-α-d-Rhap4NAc-1-O-(CH2)5COOMe, α-d-Rhap4NAc-(1→2)-α-d-Rhap4NAc-(1→3)-α-d-Rhap4NAc-(1→3)-α-d-Rhap4NAc-1-O-(CH2)5COOMe, and α-d-Rhap4NAc-(1→3)-α-d-Rhap4NAc-(1→2)-α-d-Rhap4NAc-(1→3)-α-d-Rhap4NAc-(1→3)-α-d-Rhap4NAc-1-O-(CH2)5COOMe] were synthesized in a stepwise fashion from 5-methoxycarbonylpentyl 4-azido-4,6-dideoxy-2-O-benzyl-α-d-mannopyranoside and orthogonally protected 1-thioglycoside glycosyl donors. The amorphous, final products were fully characterized as corresponding per-O-acetyl derivatives.