CHEMICAL SYNTHESIS OF A HEXASACCHARIDE COMPRISING THE LEWIS(X) DETERMINANT LINKED BETA-(1-]6) TO A LINEAR TRIMANNOSYL CORE AND THE PRECURSOR PENTASACCHARIDE LACKING FUCOSE

摘要

Phenyl 2,3,4-tri-O-acetyl-6-O-chloroacetyl-1-thio-alpha, beta-mannopyranoside (5) was condensed with benzyl O-(2,3,4-tri-O-benzyl-beta-D-mannopyranosyl)-(1-->6)-2,3, 4-tri-O-benzyl-alpha-D-mannopyranoside (12) in the presence of NIS-triflic acid to give, after removal of the chloroacetyl group, the key intermediate, benzyl O-(2,3,4-tri-O-acetyl-alpha-D-mannopyranosyl)-(1-->6)-O-(2,3, 4-tri-O-benzyl-beta-D-mannopyranosyl)-(1-->6)-2,3, 4-tri-O-benzyl-alpha-D-mannopyranoside (14). A similar condensation of 6 and 7 with acceptor 14, followed by the removal of protecting groups, afforded 16 and 18, respectively. These compounds are expected to be useful in specificity studies of an antibody raised against a related, synthetic antigen that we are currently investigating. [References: 24]