Synthesis of a mannose heptasaccharide existing in baker's yeast, Saccharomyces cerevisiae X2180-1A wild-type strain.
A mannose heptasaccharide existing in baker's yeast, Saccharomyces cerevisiae X2180-1A wild-type strain, was effectively synthesized as its allyl glycoside via TMSOTf-promoted condensation of a disaccharide donor 13 with a pentasaccharide acceptor 12, followed by deprotection. The pentasaccharide 12 was constructed by coupling of 2,3,4,6-tetra-O-benzoyl-alpha-D-mannopyranosyl-(1-->3)-2,4,6-tri-O-benzoyl-alpha-D-mannopyranosyl-(1-->2)-3,4,6-tri-O-benzoyl-alpha-D-mannopyranosyl-(1-->2)-3,4,6-tri-O-benzoyl-alpha-D-mannopyranosyl trichloroacetimidate (9) with allyl 6-O-acetyl-3,4-di-O-benzoyl-alpha-D-mannopyranoside (10), followed by deacetylation. The tetrasaccharide 9 was obtained by coupling of 2,3,4,6-tetra-O-benzoyl-alpha-D-mannopyranosyl-(1-->3)-2,4,6-tri-O-benzoyl-alpha-D-mannopyranosyl trichloroacetimidate (5) with allyl 3,4,6-tri-O-benzoyl-alpha-D-mannopyranosyl-(1-->2)-3,4,6-tri-O-benzoyl-alpha-D-mannopyranoside (6), followed by deallylation and trichloroacetimidation. The disaccharides 6 and 13 were readily obtained by known methods.
Zeng
Youlin
Y
Research Center for Eco-Environmental Sciences, Academia Sinica, P.O. Box 2871, Beijing 100085, China.
Zhang
Jianjun
J
Ning
Jun
J
Kong
Fanzuo
F
D002240:Carbohydrate Sequence; D008351:Mannans / Q000737:chemistry; D008358:Mannose / Q000737:chemistry*; D009844:Oligosaccharides / Q000138:chemical synthesis*; D012441:Saccharomyces cerevisiae / Q000737:chemistry*
D008351:Mannans; D009844:Oligosaccharides; D008358:Mannose