SnCl2‐Catalyzed Acetalation/Selective Benzoylation Sequence for the Synthesis of Orthogonally Protected Glycosyl Acceptors

Abstract Based on SnCl2‐catalyzed acetalation and selective benzoylation, a one‐pot strategy to efficiently synthesize orthogonally protected glycosyl acceptors with 2‐OH/3‐OH was developed. Consequently, 2‐OBz or 3‐OBz 4,6‐O‐benzylidene galactosides and glucosides were efficiently prepared in moderate to high yields starting from free galactosides and glucosides, and were used as valuable glycosyl acceptors for the synthesis of blood group antigens O and B analogues in this study.