Synthesis of model compounds related to linear β-d-(1→6)-galactosyl side-chains of polysaccharides from astragalus mongholicus bunge

Stereocontrolled efficient syntheses of β-d-(1→6)-linked di-, tetra- and octa-galactans as model compounds of arabino-3,6-galactans isolated from Astragalus mongholicus are described. The syntheses consisted of simple glycosylation cycles: an acceptor and a donor prepared from a common compound were coupled, and the glycosylation product was converted to the acceptor and donor of the next glycosylation.