Glucopyranoside catalytic oxidation

Table II lists derivatives of D-glucuronic acid which have been obtained by catalytic oxidation. A ready preparation of 3-0-methyl-D-glucuronic acid is by the oxidation of l,2-0-isopropylidene-3-0-methyl-D-gluco-furanose and subsequent hydrolysis of the product." 4-0-Methyl-D-glucuronic acid, a compound of considerable interest because of its occurrence as a fundamental unit in hemicelluloses" and polysaccharides," cannot be obtained by the simple catalytic oxidation of methyl 4-0-methyl-D-glucopyranoside. f...

In a similar manner, methyl a-D-glucopyranoside (8, R = Me) can be oxidized catalytically in 87% yield to methyl a-D-glucopyranosiduronic acid (9, R = Me). This, however, is only converted to D-glucuronic acid in low yield, because of the necessarily severe conditions of acid hydrolysis. The total yield of n-glucurono-6,3-lactone amounts to 16%. A yield of 68% is obtained from the oxidation of methyl d-D-glucopyranoside. After hydrolysis with formic acid, D-glucurono-6,3-lactone is obtained in an over-all yield of 15%. 

The methods of synthesis of uronic acids by catalytic and nonspecific oxidation of sugars has been reviewed,and a study of the oxidation of octyl a-D-glucopyranoside to octyl a-o-glucopyranosiduronic acid by sodium hypobromite catalysed by some ruthenium complexes has been reported. The stability constants of metal ion-uronic acid complexes have been reviewed. ... 

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