Synthesis of a mannose heptasaccharide of the pathogenic yeast, Candida glabrata IFO 0622 strain.
An effective synthesis of the mannose heptasaccharide existing in the pathogenic yeast, Candida glabrata IFO 0622 strain was achieved via TMSOTf-promoted condensation of a tetrasaccharide donor 13 with a trisaccharide acceptor 16, followed by deprotection. The tetrasaccharide 13 was constructed by coupling of 2,3,4,6-tetra-O-benzoyl-alpha-D-mannopyranosyl-(1-->3)-2,4,6-tri-O-acetyl-alpha-D-mannopyranosyl trichloroacetimidate (7) with allyl 3,4,6-tri-O-benzoyl-alpha-D-mannopyranosyl-(1-->2)-3,4,6-tri-O-benzoyl-alpha-D-mannopyranoside (10), followed by deallylation and trichloroacetimadation. The trisaccharide 16 was obtained by coupling of 6-O-acetyl-2,3,4-tri-O-benzoyl-alpha-D-mannopyranosyl trichloroacetimidate with 10, and subsequent 6-O-deacetylation. The disaccharide 7 was prepared through coupling of perbenzoylated mannosyl trichloroacetimidate with 4,6-O-benzylidene-1,2-O-ethylidene-beta-D-mannopyranose, then simultaneous debenzylidenation and deethylidenation, and subsequent acetylation, selective 1-O-deacetylation, and trichloroacetimidation. The disaccharide 10 was obtained by self-condensation of 3,4,6-tri-O-benzoyl-1,2-O-allyloxyethylidene-beta-D-mannopyranose, followed by selective 2-O-deacetylation.
Research Center for Eco-Environmental Sciences, Academia Sinica, Chinese Academy of Sciences, PO Box 2871, Beijing 100085, PR China.
Youlin
Y
Zeng
Jianjun
J
Zhang
Fanzuo
F
Kong
D041221:Candida glabrata / Q000737:chemistry*; D002240:Carbohydrate Sequence; D008362:Mannosides / Q000138:chemical synthesis* / Q000737:chemistry; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000138:chemical synthesis* / Q000737:chemistry
D008362:Mannosides; D009844:Oligosaccharides