Glucopyranosiduronic acid, methyl preparation

A number of /i-D-glucopyranosiduronic acids have been prepared from methyl 2,3,4-tri-O-acetyl-1 -bromo-1 -deoxy-/J-D-glucopyranuronate (85), a compound initially prepared by Goebel and Babers by the action of hydrogen bromide in acetic acid on methyl tetra-O-acetyl-a- or fi-D-glucopyranuronates.245... 

The 2-, 3-, 4-, and 6-monosulphates of methyl a-D-galactopyranoside and the 2-and 3-monosulphates of methyl a- and j8-D-glucopyranosiduronic acid have been prepared by standard methods. Sulphates or mixtures of sulphates and cyclic sulphates were produced when benzyl 2,3-anhydro-4-0-triflylpentopyranosides were treated with t-BUOSO3H. An example is presented in Scheme 15. The conversion of cyclic sulphates to epoxides is covered in Chapter 5. 

Condensation of the appropriate per-O-acetylated glycopyranosyl bromide with 4-aminobenzenethiol in the presence of sodium methoxide has been used to prepare 4-aminophenyl l-thio-j3-D-gluco-, -galacto-, and -xylo-pyranosides and 4-aminophenyl 2-acetamido-2-deoxy-1 -thio-jS-D-glucopyranoside. 4-Amino-phenyl l-thio-/3-D-glucopyranosiduronic acid was synthesized by condensation of methyl (2,3,4-tri-O-acetyI-a-D-glucopyranosyl bromide)uronate with 4-aminobenzenethiol, followed by saponification with sodium hydroxide. An attempt to obtain the l,2-ci5-l-thioaldopyranoside by reaction of 4,6-di-0-acetyl-2,3-0-carbonyl-a-D-mannopyranosyl bromide (191) with sodium 4-nitrobenzene-... 

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