Synthesis of Alginate Oligosaccharides Containing L-Guluronic Acids

Making ends meet: The L-gulopyranosyl trichloroacetimidate and 1,6-anhydro-2,3-di-O-benzyl-beta-L-gulopyranose, efficiently derived from L-ascorbic acid, were individually used as a starting unit and an elongation unit to prepare L-guluronic acid linked alginate oligosaccharides in excellent alpha selectivity and in good yields.