Synthetic antigens: Synthesis of 4-aminophenyl o-α-D-mann0pyran0syl-(l->2)-O-α-D-mannopyranosyl-(1->6)-O-α-D-mannopyranoside and a related DI- and a trisaccharide¹

4-Nitrophenyl 2, 3-O-isopropylidine-α-D-mannopyranoside 2 was condensed with 0(2, 3, 4, 6-tetra-O-acetyl-α-D-mannopyranosyl)-(l—>2)-3, 4, 6-tri-O-acetyl-α-D-mannopy-ranosyl bromide 1 and 2, 3, 4, 6-tetra-O-acetyl-α-D-mannopyranosyl bromide 11 in the presence of mercuric cyanide. Products were deprotected to yield, respectively, 4-nitrophenyl O-α-D-mannopyranosyl-(l—>2)-O-α-D-mannopyranosyl-(l->6)-α-D-manno-pyranoside 6 and 4-nitrophenyl O-α-D-mannopyranosyl-(l->6)-α-D-mannopyranoside 14. The 4-nitrophenyl group of 6 was reduced to give title trisaccharide. Bromide 1 was also condensed with methyl 2, 3, 4-tri-Obenzyl-α-D-manopyranoside 3 in the presence of silver trifluoromethanesulfonate and tetramethylurea to give protected trisaccharide derivative which was deprotected to furnish, methyl O-α-D-mannopyranosyl-(l—>2)-O-α-D-mannopyranosyl~(l—>6)-α-D-mannopyranoside 10 The identities of all protected and deprotected compounds were supported by ¹H and ¹³C NMR spectral data.