1402803-08-0Relevant academic research and scientific papers
Synthesis of 4 manipulated Lewis X trisaccharide analogues
Moore, Christopher J.,Auzanneau, France-Isabelle
, p. 1134 - 1143 (2012/09/08)
Three analogues of the Lex trisaccharide antigen (β-D-Galp(1→4)[α-L-Fucp(1→3)]-D-GlcNAcp) in which the galactosyl residue is modified at O-4 as a methyloxy, deoxychloro or deoxyfluoro, were synthesized. We first report the preparation of the modified 4-OMe, 4-Cl and 4-F trichloroacetimidate galactosyl donors and then report their use in the glycosylation of an N-acetylglucosamine glycosyl acceptor. Thus, we observed that the reactivity of these donors towards the BF3OEt 2-promoted glycosylation at O-4 of the N-acetylglucosamine glycosyl acceptors followed the ranking 4-F > 4-OAc ≈ 4-OMe > 4-Cl. The resulting disaccharides were deprotected at O-3 of the glucosamine residue and fucosylated, giving access to the desired protected Lex analogues. One-step global deprotection (Na/NH3) of the protected 4 -methoxy analogue, and two-step deprotections (removal of a p-methoxybenzyl with DDQ, then Zemplen deacylation) of the 4 -deoxychloro and 4 -deoxyfluoro protected Lex analogues gave the desired compounds in good yields.
