Synthesis of Lex-neoglycoconjugate to study carbohydrate-carbohydrate associations and its intramolecular interaction

A straightforward synthetic strategy for the preparation of the Le(x) neoglycoconjugate (11,11'-dithio bis[undecanyl-beta-D-galactopyranosyl-(1-->4)-alpha-L-fucopyranosyl-(1-->3)-2-acetamido-2-deoxy-beta-D-glucopyranoside]) and methyl Le(x) glycoside starting from the same trisaccharide donor is reported. This donor represents a very useful precursor for the construction of Le(x) derivatives. The Le(x) neoglycoconjugate has allowed the preparation of polyvalent gold glyconanoparticles and self-assembled monolayers on gold. H-1 NMR of the Le(x) neoglycoconjugates suggests an intramolecular Le(x)-Le(x) cis-interaction in water, which is destroyed by addition of methanol. (C) 2002 Elsevier Science Ltd. All rights reserved.