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Glucofuranosidurono-6,3-lactone preparation

Because of the particular structural features of compound 4, pointed out in Section I, the D-glucofuranosyluronic halide anomers not only have inverse thermodynamic stabilities with respect to those of D-glucopyranosyl halides but also show a different behavior towards alcohols. For instance, 2,5-di-O-acyl-a-D-gluco-furanosylurono-6,3-lactone halides, which are difficult to prepare, do not react with alcohols, inasmuch as an endo approach of the reagent is inhibited.14 The /3-bromides and -chlorides, however, just like /3-D-glucopyranosyl chlorides, are subject to alcoholysis, with formation of /3-D-glucofuranosidurono-6,3-lactones.16... [Pg.195]

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). [Pg.197]

Esters of 4, which are used as substrates for the preparation of D-glucofuranosylurono-6,3-lactone halides (see Section 1,1) or aryl D-glucofuranosidurono-6,3-lactones (see Section 1,2), are prepared by reaction of 4 with acid halides or anhydrides in the presence of a basic or an acidic catalyst. [Pg.203]

Some long chain alkyl P-D-glycosides of D-glucofuranosidurono-6,3-lactone have been prepared by acid-catalysed glycosidation the glucuronides wa-e also reduced to alkyl p-D-glucofuranosides. ... [Pg.210]


See other pages where Glucofuranosidurono-6,3-lactone preparation is mentioned: [Pg.204]    [Pg.217]    [Pg.230]    [Pg.423]    [Pg.147]   
See also in sourсe #XX -- [ Pg.33 , Pg.196 , Pg.203 , Pg.204 , Pg.205 ]




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Glucofuranosidurono-6,3-lactone

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