One-pot synthesis of a 3,6-branched hexaarabinogalactan using galactopyranosyl thioglycoside diol as a key glycosylating agent.

We present in this paper the efficient four-component one-pot synthesis of a fully protected hexaarabinogalactan 2 with di-branched structure by using D-thiogalactopyranoside 3,6-diol 3 as the central glycosylating agent. After global deprotection, 2 was converted into the 3-aminopropyl linker-containing free oligosaccharide 1 that is structurally related to ALR-5IIa-1-1, an arabino-3,6-galactan with intestinal immune system modulating activity.