Selection of protecting groups and synthesis of a β-1,4-GlcNAc-β-1,4-GIcN unit

摘要

The synthesis of the disaccharide tert-butyldimethylsilyl (4-O-acetyl-2-azido-3,6-di-O-benzyl-2-deoxy-β-D-glucopyranosyl)-3,6-di-O-benzyl-2-deoxy-2-phthalimido-β-D-glucopyranoside, designed as a repeating unit appearing in oligo- and polysaccharides, which exhibits a distinguished "obverse-reverse" property in β-1,4-glucan chain, was accomplished. This disaccharide was synthesized by glyco-sylation of a phthalimido sugar with an azido sugar. A selective removal of the two different protecting groups at C-2 for obtaining 2-acetamido-4-O-(2-amino-2-deoxy-β-D-glu-copyranosyl)-2-deoxy-β-D-glucopyranose indicates that the selection and combination, using phthalimido and azido as protecting groups, are an excellent strategy for synthesizing such target disaccharides.