Synthesis of Alginate Oligosaccharides Containing L‐Guluronic Acids

Making ends meet: The L‐gulopyranosyl trichloroacetimidate and 1,6‐anhydro‐2,3‐di‐O‐benzyl‐β‐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 α selectivity and in good yields. Making ends meet: The L‐gulopyranosyl trichloroacetimidate and 1,6‐anhydro‐2,3‐di‐O‐benzyl‐β‐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 α selectivity and in good yields.