Synthesis of the Forssman pentasaccharide and terminal tetra-, tri-, and di-saccharide fragments.
The 2-(trimethylsilyl)ethyl (TMSEt) beta-glycosides of the Forssman pentasaccharide [alpha-D-GalNAc-(1-->3)-beta-D-GalNAc-(1-->3)-alpha-D-Gal- (1-->4)-beta-D-Gal-(1-->4)-D-Glc] and the terminal tetrasaccharide, as well as the methyl glycosides 1 and 2 of the terminal di- and tri-saccharides, were synthesised by silver trifluoromethanesulfonate-promoted alpha-glycosylation of suitably protected mono-, di-, tri-, and tetrasaccharide alcohols with 3,4,6-tri-O-acetyl-2-azido-2-deoxy-alpha-D-galactopyranosyl bromide, followed by removal of protecting groups. The anomeric TMSEt group of the Forssman pentasaccharide and terminal tetrasaccharide was removed with trifluoroacetic acid-dichloromethane, to give the corresponding hemiacetal sugars 4 and 6.
Nilsson
U
U
Chemical Center, Lund Institute of Technology, University of Lund, Sweden.
Ray
A K
AK
Magnusson
G
G
D002240:Carbohydrate Sequence; D004187:Disaccharides / Q000138:chemical synthesis*; D005577:Forssman Antigen / Q000737:chemistry*; D005915:Globosides / Q000737:chemistry*; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000138:chemical synthesis*; D014312:Trisaccharides / Q000138:chemical synthesis*
D004187:Disaccharides; D005915:Globosides; D009844:Oligosaccharides; D014312:Trisaccharides; C035968:globotetraose; D005577:Forssman Antigen