Improved synthesis of an aldobiouronic acid related to hardwood xylans, and preparation of a derivative thereof suitable for linking to proteins.
Treatment of 1,3,4-tri-O-acetyl-alpha-D-xylopyranose with methyl 2,3-di-O-benzyl-l-chloro-l-deoxy-4-O-methyl-alpha, beta-D-glucopyranuronate in the presence of silver trifluoromethanesulfonate was highly stereoselective to give the alpha-linked aldobiouronic acid derivative (4) in 86% yield, after hydrogenolysis of the crude product of the coupling and chromatography. Compound 4 was acetylated and the fully protected substance was converted to the corresponding glycosyl chloride. Reaction of the latter with p-nitrophenol under phase-transfer catalysis afforded, after deacetylation, p-nitrophenyl 2-O-(methyl 4-O-methyl-alpha-D-glucopyranosyluronate)-beta-D-xylopyranoside.
Hirsch
J
J
Institute of Chemistry, Slovak Academy of Sciences, Bratislava, Slovak Republic.
Koós
M
M
Kovác
P
P
D006023:Glycoproteins / Q000138:chemical synthesis*; D013400:Sugar Acids / Q000138:chemical synthesis* / Q000737:chemistry; D014934:Wood; D014990:Xylans / Q000737:chemistry*
D006023:Glycoproteins; D013400:Sugar Acids; D014990:Xylans