Xylose 2-deoxy

Generally speaking, the phosphorylated deoxysugars undergo the usual reactions of carbohydrates without complication. For instance, both 2-deoxy D-ribose 5-phosphate (52, 59) and 2-deoxy D-xylose 5-phosphate (2) can be reduced to the corresponding 2-deoxy d-erythro- (48) and 2-deoxy D-threo-pentitol 5-phosphates (49). 2-deoxy ribose 5-phosphate has also been oxidized (52) to the corresponding phosphorylated acid (50). 

Deoxy-sugars. Part II. Synthesis of 2-Deoxy-D-ribose and 3-Deoxy-D-xylose from D-Arabinose, P. W. Kent, M. Stacey, and L. F. Wiggins,/. Chem. Soc., (1949) 1232-1235. 

The Oxidation of Some Carbohydrate Derivatives using Acetic Anhydride - Methyl Sulphoxide Mixtures and the Pfitzner-Moffat Reagent. Facile Synthesis of 3-Acetamido-3-deoxy-D-glucose and 3-Amino-3-deoxy-D-xylose, J. S. Brimacombe, J. G. H. Bryan, A. Husain, M. Stacey, and M. S. 

Enzymic syntheses are considered next. Xylitol is a substrate for sheep-liver L-iditol dehydrogenase, a NAD-linked enzyme. 1-Deoxy-D-xylitol, prepared by Raney nickel reduction of D-xylose diethyl dithioacetal in a 27% overall yield from D-xylose, was also reported31 to be a substrate, although with a higher Km and lower Vmax. The product was assumed to be l-deoxy-D-f/ireo-pentulose because of the appearance of a yellowish fluorescent spot when a chromatogram was sprayed with acidic 3,5-aminobenzoic acid, resembling that formed from 1 -deoxyfructose. There was no more-rigorous characterization. 

RG-n, Rhamnogalacturonan II Kdo, 3-deoxy-D-manno-octulosonic acid Dha, 3-deoxy-D-/yxo-heptulosaric acid aceric acid, 3-C- carboxy-5-deoxy-L-xylose TMS, per-0-trimethylsilylated methyl glycosides. 

Acetaldehyde combines with 2,3-O-isopropylidene-D-glycerose, in the presence of potassium carbonate, to give 2-deoxy-4,5-O-isopropylidene-D-ribose and -D-xylose,46 suggesting a possible biosynthetic route (see Reference 46). The suggestion that 2-deoxy-D- ribose (2-deoxy-D-erythro-pentose) arises by combination of acetaldehyde with D-glycerose 3-phosphate to give 2-deoxy-D-ribose 5-phosphate (LX) was verified by using enzyme... 

D-Lyxose yielded a D-lyxosyl chloride 2,3,4-tri(chlorosulfate) which, on treatment with chloride ion, led to a dichlorodideoxy compound, most probably 2,4-dichloro-2,4-dideoxy-L-arabinose.353 D-Glucose gave a compound presumed to be 4,6-dichloro-4,6-dideoxy-a,/3-D-galactosyl chloride 2,3-di(chlorosulfate),360 and D-xylose afforded a monochloromonodeoxy derivative formulated, on indirect evidence, as 4-chloro-4-deoxy-L-arabinopyranosyl chloride 2,3-di(chlorosulfate).360 3,4-Dichloro-3,4-dideoxy-/3-D-ribopyranosyl chloride 2-(chlorosulfate) was the major, and 4-chloro-4-deoxy-a-D-xylopyranosyl chloride 2,3-di(chlorosulfate) the minor, product from the reaction of L-arabinose with sulfuryl chloride at room temperature for 24 hours.357,361 It has been established that, on reaction with sulfuryl chloride at low temperature, crystalline a-D-xylopyranose and /3-D-lyxopyranose afford, respectively, the 2,4,6-tri(chlorosul-fate)s of /3-D-xylopyranosyl chloride and a-D-lyxopyranosyl chloride,362 363 confirming that substitution at C-l occurs by an Sn2 process on a l-(chlorosulfuric) ester intermediate. 

Another relevant example is found with the addition of 3-aminopropan-l-ol to 5-bromo-5-deoxy-D-xylose. The formation of the least stable stereomer 58 is 20 times as fast as that of 59 (at equilibrium [59]/[58] = 7.3).49 This kinetic selectivity was interpreted in terms of transition structures 60 and 61 which imply IV-alkylation of a tetrahydrooxazine intermediate as the discriminating step. The faster formation of the least stable product 58 arises from transition state 60 in which IV-alkylation corresponds to an axial attack of the oxazine intermediate. This is easier than equatorial attack in transition state 61 (Fig. 20). 

D-ribofuranosidell8(30 and 32) (or potassium hydrogenfluoride and sodium fluoride in the latter case119) yielded 2-deoxy-2-fluoro-D-arabi-nose (31) and 3-deoxy-3-fluoro-D-xylose (33), respectively, after deprotection. 

The availability, in gram quantities, of the fluorinated carbohydrates thus far synthesized has also made possible their use as starting materials for the synthesis of other analogs and intermediates for example, the preparation of 3,5-dideoxy-3,5-difluoro-D-xylose from 3-deoxy-3-fluoro-D-xylose,88 which is itself preparable from 3-deoxy-3-fluoro-l,2-0-isopropylidene-a-D-glucofuranose. Electrolytic oxidation of 3-deoxy-3-fluoro-D-glucose afforded, after treatment with an acidic... 

Several 2-amino-2-deoxy-D-gulononitrile derivatives (68) have been obtained by treating D-xylose with hydrogen cyanide and an amine. Among the amines that were used in preparing these derivatives were aniline,107-109 9-aminofluorene,110 p-methylphenylamine,109 and benzylamine.109 In all cases, as expected, both the D- and L-gly-cero configurations at C-2 are formed. When a solution of 68 (R = Ph)... 

On treatment of 2,3 4,5-di-0-isopropylidene-D-xylose with cyclohexyl isonitrile and ammonium acetate, 2-acetamido-N-cyclohexyl-2-deoxy-3,4 5,6-di-0-isopropylidene-D-gulonamide was formed112 it was reported that only one isomer was produced in this reaction. 

The rate of oxidation of other monosaccharides (e.g. galactose, mannose, xylose, arabinose and fructose) by glucose oxidase has been shown to be negligible or zero but some derivatives of glucose do react slightly, e.g. 2-deoxy-D-glucose shows a reaction rate of less than 5% of that with /3-D-glucose. 

Ross and Ugi" prepared l-amino-5-deoxy-5-thio-2,3,4-tri-6)-isobutanoyl-P-D-xylopyranose 61a from xylose via the 5-desoxy-5-thio-D-xylopyranose. The U-4CRs of this amine form a-aminoacid derivatives stereoselectively and in excellent yields. These products have the advantage that their products are stable and their auxiliary group 5-desoxy-5-thio-D-xylopyranose can be cleaved off selectively by mercury(II) acetate and trifluoroacetic acid. The expected steric structure of the corresponding U-4CR product was confirmed by X-ray measurement. 

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