A SHORT, EFFICIENT SYNTHESIS OF THE OCTAMANNAN-RESIDUE OF HIGH-MANNOSE TYPE SUGAR CHAINS

An efficient route for the synthesis of octamannan 1, found in high ma nnose type sugar chains, is described. To construct octasaccharide 1 b y as few synthetic steps as possible, we employed a chemoenzymatic str ategy: the enzymatic synthesis of oligosaccharide blocks using glycosi dases followed by chemical coupling to form a branched structure. By u se of this methodology, many synthetic steps were eliminated and 1 was easily synthesized.