A Convenient Synthesis of Partially Benzylated Derivative of beta-D-GlcpNAc-(1 -> 3)-beta-D-Galp-(1 -> 4)-beta-D-Glcp-1-OBn as a Versatile Building Block for Sialyl Lewis X Antigens

作者：Soliman Sameh E; Bassily Rafik W; El Sokkary Ramadan I; Nashed Mina A^*

来源：Letters in Organic Chemistry, 2015, 12(6): 413-417.

DOI：10.2174/1570178612666150415235934

• Carbohydrates
• Building block
• Oxazoline coupling
• Cyclic orthoester
• Sialyl Le(x)

Synthesis of the trisaccharide, benzyl 2-acetamido-3,6-di-O-benzyl-2-deoxy-beta-D-glucopyranosyl-(1 -> 3)-2,4,6-tri-O-benzyl-beta-D-galactopyranosyl-(1 -> 4)-2,3,6-tri-O-benzyl-beta-D-glucopyranoside (9), was achieved from building block derivatives of the component mono-and disaccharide units. Initially the benzyl lactoside acceptor 3, which has a free hydroxyl group at position O-3', was prepared via selective opening of the 3',4'-cyclic orthoester derivative 2. The glucosaminyl donor, 2-methyl (3,4,6-tri-O-acetyl-1,2-dideoxy-alpha-D-glucopyrano)-[2',1':4,5]-2-oxazoline (4), was coupled to 3 affording the trisaccharide glycoside 5 in a good yield. Successive de-O-acetylation (5 -> 6), benzylidenation (6 -> 7), benzylation (7 -> 8) and reductive opening of the benzylidene acetal function of 8 gave the target trisaccharide 9, which is a useful building block for the construction of complex oligosaccharides.

• 出版日期2015
• 单位NIH