Approach to the synthesis of the repeating units of immunodeterminant bacterial polysaccharides: synthesis and 13C n.m.r. analysis of β-D-galactopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-L-rhamnopyranose

Abstract

The title tetrasaccharide was obtained by reaction of the α-acetobromo derivative (6) of 3-O-β-D-galactopyranosyl-L-rhamnose (4) and benzyl3,4-di-O-benzyl-2-O-(2,4,-di-O-benzyl-α-L-rhamnopyranosyl)-α-L-rhamnopyranoside (11), followed by removal of the protecting groups.