Glucofuranurono-6,3-lactones reactions

D-Glucofuranurono-6,3-lactone, reactions of, 33, 189-234 Gottschalk, Alfred, obituary of, 33, 1-9... 

Because direct glycosidation of 4 with phenols is not possible, indirect methods must be used for the preparation of aryl D-glucofuranosidurono-6,3-lactones (29). In addition, aryl 2,5-di-O-acetyl-D-glucofuranosidurono-6,3-lactones (30), obtained35-37 from the reaction of 1,2,5-tri-0-acetyl-D-glucofuranurono-6,3-lactones with phenols, can only be deacetylated by such multi-step procedures as (1) ammonolysis of 30 to afford aryl D-glucofuranosiduronamides (31), followed by amide hydrolysis and lactonization, 35,37 or (2) reduction of 30 with lithium aluminum hydride, and subsequent oxidation of the intermediate aryl D-glucofuranosides38 (32) (see Scheme 1). 

Specifically, in reactions of 4 with acetic anhydride in the presence of zinc chloride58 or boron trifluoride17,35 as the catalyst, 1,2,5-tri-O-acetyl-/J-D-glucofuranurono-6,3-lactone (12) is the preponderant product in the presence of pyridine,58 however, acetylation of 4 by acetic anhydride leads to the favored formation of the corresponding a-D anomer. In contrast to acetylations, in benzoylation reactions, the ratio of anomers apparently changes. Thus, on treatment of 4 with benzoyl chloride in pyridine, Momose and coworkers17 isolated... 

VI. Reactions Involving the Lactone Ring of Derivatives of d-Glucofuranurono-6,3-lactone... 

A very low yield of l,2-0-isopropylidene-5-0-p-tolylsulfonyl-o -D-glucofuranuronamide was obtained113 on ammonolysis of the corresponding 5-O-p-tolylsulfonyl lactone (52) with ammonia in methanol at low temperature. In a similar reaction of l,2-0-isopropylidene-5-0-(methylsulfonyl)-a-D-glucofuranurono-6,3-lactone (50), formation of substantial proportions of l,2-0-isopropylidene-5-0-(methylsul-fonyl)-Q -D-glucofuranuronamide could be observed110 in the reaction mixture however, on evaporation, the starting material was reformed. 

On reaction with hydroxylamine in the presence of appropriate bases, such derivatives of D-glucofuranurono-6,3-lactones as 25, 26, and 33 form114 N-hydroxyamides. On the other hand, when treated with hydroxylamine without base catalysis, compound 4 yields115 aWeJjt/do-D-glucurono-6,3-lactone oxime. 

Reaction of 5-0-Benzyl-l,2-0-isopropylidene-a-D-glucofuranurono-6,3-lactone (45) with Sodium Borohydride in Various Aprotic, Dipolar Solvents to Yield 2-0-Benzyl-3-deoxy-L-[Pg.220]

Deoxy-D-vy/o-hexuronic acid was obtained in good yield via the reaction of 1,2-0-cyclohexyliden-5-0-(methylsulfonyl)-a-D-glucofuranurono-1,4-lactone with hydrazine.196... 

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