Glucopyranuronic acid preparation

Preparation of 2,3,4-tri-0-acetyl-l-0-[4-[ /- Hs-(3R,4.S )-3-[3-(.S )-acetyloxy-3-(4-fluorophenyl)propyl]-l-(4-fluorophenyl)-2-oxo-4-azetidinyl]phenyl]-p-D-glucopyranuronic acid methyl ester... 

D-glucopyranuronic acids have been prepared by Koenigs-Knorr syn-... 

Derivatives of 2-amlno-2-deojqr-D-glucopyranuronic acid nucleosides (86) have been prepared by conventional coupling procedures, and uronic ester nucleosides of type (87) give the 4, 5 -ene on treatment with... 

Pivaloyl-p-D-glucopyranuronic acid has been prepared in order to identify it as a metabolite of pivaloyloxyalkyl-containing prodrugs, the acid grouping being introduced by catalytic oxidation. i Electrochemical oxidation of some carbohydrate primary alcohols at a nickel hydroxide electrode in alkaline solution has been developed as a route to uronic acids. Examples... 

The main Phase II metabolite of valproic acid (29), a broad spectrum anticonvulsant, is the acyl glucuronide l-0-valproyl-/3-D-glucopyranuronic acid (30). This metabolite was prepared in carbon-14 and tritium-labeled forms enzymatically in one step in around 52% yields using UDP-glucuronosyltransferase . The positions of labels were not specified. In contrast, the chemical synthesis starting from valproic acid and 2,3,4,6-tetrabenzyl-D-glucopyranose required three steps and provided the required /3-anomer in only 6.8% yield. 

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... 

Attempts to use a Lewis acid to anomerize the ester linkage at C-l from /3 to a have thus far been mostly unsuccessful however, application of Bonner s249 procedure, involving anomerization of acetylated aldoses in an acid anhydride containing an acid catalyst, was found246 to be applicable to the acetylated D-glucopyranuronate series also. Thus, /3 —> a anomerization of methyl tri-0-acetyl-l-0-propanoyl-/3-D-glucopyranuronate (prepared by the silver salt method) was achieved... 

Oxidation of primary alcohols. The metal-catalyzed oxidation of primary alcohols (only) to carboxylic acids usually employs platinum, as shown in a procedure for the preparation of alkyl glucopyranuronates. A palladium/carbon-lead(II) acetate system is also serviceable. ... 

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