Block Synthesis of Tetra- and Hexasaccharides (β-d-Glycero-d-manno-Hepp-(1→4)-[α-l-Rhap-(1→3)-β-d-glycero-d-manno-Hepp-(1→4)]n-α-l-Rhap-OMe (n = 1 and 2)) Corresponding to Multiple Repeat Units of the Glycan from the Surface-Layer Glycoprotein from Bacillus thermoaerophilus
摘要:
A fully stereocontrolled block synthesis of the title tetra- and hexasaccharides has been achieved taking advantage of the ability of the 4,6-O-benzylidene acetal to control the stereochemistry of the beta-D-glycero-D-mannoheptopyranoside unit and of a 2,3-O-diphenylmethylene acetal to install the alpha-L-rhamnopyranosidic linkages. Comparison of the spectral data for the hexasaccharide with that of the natural isolate confirms the structure of this very unusual and structurally challenging glycan.
Block Synthesis of Tetra- and Hexasaccharides (β-d-Glycero-d-manno-Hepp-(1→4)-[α-l-Rhap-(1→3)-β-d-glycero-d-manno-Hepp-(1→4)]n-α-l-Rhap-OMe (n = 1 and 2)) Corresponding to Multiple Repeat Units of the Glycan from the Surface-Layer Glycoprotein from Bacillus thermoaerophilus
摘要:
A fully stereocontrolled block synthesis of the title tetra- and hexasaccharides has been achieved taking advantage of the ability of the 4,6-O-benzylidene acetal to control the stereochemistry of the beta-D-glycero-D-mannoheptopyranoside unit and of a 2,3-O-diphenylmethylene acetal to install the alpha-L-rhamnopyranosidic linkages. Comparison of the spectral data for the hexasaccharide with that of the natural isolate confirms the structure of this very unusual and structurally challenging glycan.