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Deoxyfluoro sugar synthesis

The nucleophile for which increased reactivity is most critical is the fluoride ion [3,4], Water molecules bind tightly to this ion, and their presence dramatically reduces its effective nucleophilicity. A variety of fluoride ion sources have been used in an effort to improve product yields in deoxyfluoro sugar synthesis [26,34]. The yields of substitution and elimination products generated from reactions with fluoride ion from several sources are listed in Table 2 [26]. Currently, the most attractive source of fluoride ion is tris(dimethylanuno)-5ulfur (trimetbylsilyl)difluoride (TASF), which is soluble in a variety of oiganic solvents and produces an anhydrous fluoride ion [33]. [Pg.96]

The search for new methods of synthesis of halogenated carbohydrates continues to be an active area of investigation. The compounds are of utility as synthetic intermediates, and many of them are of intrinsic value in biochemistry and pharmacology. In the present Chapter methods for the synthesis of deoxyfluoro sugars and glycosyl fluorides are discussed. [Pg.2]

B. Doboszewski, G. W. Hay, and W. A. Szarek, The rapid synthesis of deoxyfluoro sugars using tris(diinethylamim)8ulfoiiiuin difliiorotrimethylsihcate (TASP), Con. J. Chem. 65 412 (1987). [Pg.103]

The above-discussed methods are mainly used for the synthesis of chloro, bromo and iodo sugars. A different approach has to be taken when a deoxyfluoro sugar derivative is required, and the most commonly applied reagent for direct fluorination is diethylaminosulfur trifluoride... [Pg.59]

The first preparation of a secondary deoxyfluoro sugar, other than by total synthesis, involved the cleavage of 2,2 -anhydro-3-( 8-D-arabino-furanosyl) uracil (3) to give 3-(2-deoxy-2-fluoro-/3-D-ribosyl) uracil. This reaction, which can be extended to cleavage by hydrogen bromide or chloride, is at pr ent the only route to 2-deoxy-2-fluoro-D-ribose deriva-... [Pg.190]

In general, when the C-F bond is retained, the early biochemical rationale for the synthesis of deoxyfluorinated sugars has now been illustrated by numerous examples. Our own studies indicate that deoxyfluoro sugars may serve as novel membrane, enzyme and metabolic probes. Additionally, as a result of demonstrated incorporation and/or lethal synthesis", fluorinated sugars have considerable potential to augment the antibiotic and antiviral arsenal. [Pg.133]

When the A-tosylaziridine 11 was opened with fluoride (KHFj, DMF, 150°C) initially the 2-fluoride 12 was produced, but over time the thermodynamic product 13 formed, presumably by reversal back to 11. This reaction was also utilized in the synthesis of fluorinated kanamycin derivatives." These and other syntheses of 4 -deoxy-4 -fluorokanamycins A and B are covered in Chapter 19. The synthesis of a fluorinated analogue of the acceptor of bovine (l- 4)-P-D-galactosyl transferase is mentioned in Chapter 3, and the conformational analysis of some deoxyfluoro sugars by H-n.m.r. spectroscopy is detailed in Chapter 21. The use of e.i. and c.i. mass spectrometry to determine the location of a fluorine atom in deoxyfluoro glucosides is outlined in Chapter 22. [Pg.105]

Treatment of the D-arabino- and D-xylo-furanosides 1 and 2 with DAST afforded the deoxyfluoro derivatives 3 and 4 in the former case, whereas the latter gave the anhydro-sugar 5 and the deoxyfluoro compound 6 (Scheme 1). Osmium tetroxide-catalysed dihydroxylation of the chiral unsaturated derivative 7 led to the synthesis of 2-deoxy-2-fluoro-D-xylose and -L-lyxose." 1,2,5-Tri-deoxy-2-fluoro-1,5-imino-D-glucitol and 1,2,5-trideoxy-1 -fluoro-2,5-imino-D-... [Pg.118]

Enzymic synthesis of several hexose derivatives from dihydroxy-propanone and glyoeraldehgde derivatives included a preparation of 6-deoxy-6-fluoro-sugars. All four deoxyfluoro-oc-D-glucopyranosyl phosphates have been synthesized and their acid-catalyzed hydrolysis... [Pg.88]


See other pages where Deoxyfluoro sugar synthesis is mentioned: [Pg.55]    [Pg.55]    [Pg.55]    [Pg.55]    [Pg.3]    [Pg.3]    [Pg.227]    [Pg.90]    [Pg.106]    [Pg.15]    [Pg.52]    [Pg.60]    [Pg.238]    [Pg.41]    [Pg.60]    [Pg.240]    [Pg.161]    [Pg.115]    [Pg.103]    [Pg.352]    [Pg.112]   
See also in sourсe #XX -- [ Pg.3 , Pg.4 , Pg.5 , Pg.6 ]




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