Propargyl mediated intramolecular aglycon delivery (IAD): applications to the synthesis of core N-glycan oligosaccharides

摘要: Abstract The use of propargyl mediated intramolecular aglycon delivery (IAD) for the synthesis key Manβ(1→4)GlcNAc linkage N -glycan oligosaccharides, including core pentasaccharide, is investigated. Isomerisation a 2- O -progargyl group manno thioglycoside donors to an allene followed by iodonium ion mixed acetal formation with 4-OH protected GlcNAc acceptors, and subsequent glycosylation occurs complete control anomeric stereochemistry form linkage. A variety linear convergent approaches (1+2, 3+1, 3+2) pentasaccharide are investigated as means probing generality limitations this type β-mannoside linkages in complex oligosaccharides.