De Novo Asymmetric Synthesis of the Anthrax Tetrasaccharide by a Palladium‐Catalyzed Glycosylation Reaction

Choose your poison: In the de novo asymmetric synthesis of the anthrax tetrasaccharide 1 (25 steps from acetylfuran), the absolute configurations of three L sugars and one D sugar were set by the Noyori reduction of acetylfuran with the S,S and the R,R reagent, respectively. The configuration of the remaining carbohydrate unit was set by highly diastereoselective palladium-catalyzed glycosylation and post-glycosylation transformations.