Synthesis of a mannose hexasaccharide related to the cell wall mannan of candida dubliniensis and trychophyton mentagrophytes

Article abstract of DOI:10.1055/s-0029-1218719

2,6-Branched mannose hexasaccharide 1 related to the cell wall polysaccharide of Candida dubliniensis and Trychophyton mentagrophytes was concisely synthesized from 4-methoxyphenyl -d-mannopyranoside (6) in 11 steps in 26% total yield. The efficiency of the synthesis relies on the preparation of a trisaccharide acceptor 2 with three free hydroxy groups, which could be glycosylated with trichloroacetimidate 19 to provide the protected hexasaccharide 20 in one step. Compound 2 was obtained via sequential assembly from the building blocks, 2,6-di-O-allyloxycarbonyl-3,4-di-O-benzoyl -α-d-mannopyranose trichloroacetimidate (3), 4-methoxyphenyl 3,4-di-O-benzoyl -α-d-mannopyranoside (4), and 4-methoxyphenyl 4-O-acetyl-3-O-benzoyl -α-d-mannopyranoside (5). Structures of target compound and intermediates were characterized by ¹H and ¹C NMR, MS, HRMS, and elemental analysis. Georg Thieme Verlag Stuttgart - New York.