Synthesis of Sialyl Lewis X Ganglioside Analogs Containing A Variable Length Spacer Between the Sugar and Lipophilic Moieties¹

1. Dedicated to the memory of Professor Akira Hasegawa.

Abstract

Five sialyl Lew is X ganglioside analogs containing 4-(2-tetradecylhexadecanoylamino)benzyl group in place of ceramide and a variety of lengths of ethylene glycol chains as the spacer, have been synthesized. Glycosidation of O-(methyl 5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-D-glycero-α-D-glacto-2-nonulopyranosylonate)-(2→3)-O-(4-O-acetyl-2,6-di-O-benzoyl-β-D-galactopyranosyl)-(1→4)-O-[(2,3,4-tri-O-acetylα-L-fucopyranosyl)-(1→3)]-2,4-di-O-benzoyl-α-D-glucopyranosyl trichloroacetimidate (13) with oligo ethyleneglycol monobenzyl ether derivatives 9, 10, 11 and 12, prepared from the corresponding oligo ethyleneglycols by 4-nitrobenzylation, reduction and N-acylation with 2-tetradecylhexadecanoic acid, using boron trifluoride etherate gave the corresponding glycolipid derivatives 14, 15, 16 and 17. A similar glycosidation of 13 with 4-nitrobenzyl alcohol gave the 4-nitrobenzyl glycoside 18, which was converted via reduction of nitro group and N-acylation into the corresponding glycolipid derivative 19. Compounds 14-17 and 19 were transformed into the title compounds by O-deacylation and hydrolysis of methyl ester group in good yields.

1. Dedicated to the memory of Professor Akira Hasegawa.

Notes

1. Dedicated to the memory of Professor Akira Hasegawa.

Dedicated to the memory of Professor Akira Hasegawa