Practical synthesis of a tetrasaccharide derivative corresponding to ristomycin A and ristocetin A.
A practical synthesis of fully benzoylated tetrasaccharide, whose free form is indispensable to the antibiotic ristomycin A for the process of dimerization and binding to the cell wall, was achieved via sequential assembly of the building blocks, allyl 3,4-di-O-benzoyl-alpha-D-glucopyranoside, 2,3,4-tri-O-benzoyl-alpha-L-rhamnopyranosyl trichloroacetimidate, 2-O-acetyl-3,4,6-tri-O-benzoyl-alpha-D-mannopyranosyl trichloroacetimidate, and 2,3,5-tri-O-benzoyl-alpha-D-arabinofuranosyl trichloroacetimidate. A one-pot preparation of allyl 3,4-di-O-benzoyl-2-O-tert-butyldimethylsilyl-6-O-triphenylmethyl-alpha-D-glucopyranoside is described, and regioselective glycosylation is carried out using perbenzoylated sugar trichloroacetimidates as glycosyl donors in the presence of a catalytic amount of trimethylsilyl trifluoromethanesulfonate (TMSOTf).
Zhang
M
M
Research Center for Eco-Environmental Sciences, Academia Sinica, Beijing, People's Republic of China.
Du
Y
Y
Kong
F
F
D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D006388:Hemagglutinins / Q000737:chemistry; D007202:Indicators and Reagents; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009844:Oligosaccharides / Q000138:chemical synthesis* / Q000737:chemistry; D009904:Optical Rotation; D012310:Ristocetin / Q000737:chemistry*
D006388:Hemagglutinins; D007202:Indicators and Reagents; D009844:Oligosaccharides; D012310:Ristocetin; C016719:ristocetin A