Studies on selectin binding inhibitors: Synthesis of sialyl-Lewis x and sialyl-Lewis a epitope analogs containing 2-acetamido derivative of N-methyl-1-deoxynojirimycin

Synthesis of sialyl-Lewis x (15) and sialyl-Lewis a (17) epitope analogs containing the 2-acetamido derivative of N-methyl-1-deoxynojirimycin has been achieved. A suitably protected 2-acetamido-1-deoxynojirimycin derivative 5, prepared from 1-deoxynojirimycin via the epoxide intermediate 3, was successively coupled with methyl-1-thioglycosides of L-fucose (6) and alpha-sialyl-(2-->3)-D-galactose (9). The resulting tetrasaccharides (10 and 13) were each converted, by reductive N-methylation and deprotection, into the desired epitope analogs.