1-Arabinitol, reactions

Various cis-ot,g-epoxycarbonyl compounds are stereoselectively prepared via g-bromo-g-hydroxycarbony1 compounds by application of this Sn(ll) mediated aldol reaction to a-bromocarbonyl compounds (22). Also this reaction is employed for the stereoselective synthesis of 2-amino-2-deoxy-D-arabinitol. 

Galbis et al. described a variety of carbohydrate-based linear polyesters 61 of the poly(alkylene dicarboxylate) type that were obtained by polycondensation reactions of the alditols 2,3,4-tri-(9-methyl-L-arabinitol (9) and 2,3,4-tri-O-methyl-xylitol (10), and the aldaric acids 2,3,4-tri-(9-methyl-L-arabinaric acid (26) and 2,3,4-tri-(9-methyl-xylaric acid (27), butanediol, and adipic acid were also used as comonomers [28]. Copolyesters of the poly(aIkylene-c )-arylene dicarboxylate) type were obtained using bisphenols as comonomers (Scheme 1). Chemical polycondensation reactions were conducted in bulk or in solution. Enzymatic polycondensation reactions of adipic acid with the above-mentioned alditols were carried out successfully using Lipozyme and Novozyme 435. The hydrolytic degradations of some of these polyesters were also described. 

Copolyurethanes based on L-arabinitol and 2,2 -dithiodiethanol have been obtained by polyaddition reaction of mixtures of 2,2 -dithiodiethanol (DiT) and 2,3,4-tri-O-methyl-L-arabinitol (9) or 2,3,4-tri-O-benzyl-L-arabinitol (11) to 1,6 hexamethylene diisocyanate (HDI) [118]. 

A procedure has been reported473 for the direct determination, on a column of Polypak, of polyhydric compounds without conversion into derivatives. Separation of pentitols was not complete, but the method was found excellent for determining the amount of one alditol, as in the oxidation of L-arabinitol by Acetobacter suboxydans. This rapid method of monitoring the utilization of L-arabinitol permitted the reaction to be stopped as soon as all of the substrate had been consumed, before side reactions interfered. 

From such a reaction scheme, it would, however, be expected that a derivative (44) of 2,5-anhydro-D-arabinitol would be obtained from 3,4-di-0-acetyl-l,5-anhydro-2-deoxy-D-erythro-pent-l-enitol (39a), and not the ribo product observed. 

In contrast to ribitol and xylitol (which form a dl mixture on anhydride formation because of their molecular symmetry), D-arabinitol may, in principle, on heating with acid, give two different anhydrides, namely, a 1,4-anhydroarabinitol ora 2,5-anhydroarabinitol (1,4-anhydro-lyxitol), as the following reaction sequence illustrates. 

Pentadienone (divinyl ketone) was epoxidized55 by means of hydrogen peroxide in alkaline solution, to give a mixture of DL- and me.so-l,2 4,5-dianhydro-3-pentanones in the ratio of 13 7. Reduction of the ketone group in the DL-diepoxide with sodium horohvdride, followed by alkaline hydrolysis in dimethyl sulfoxide, was fully stereo-specific, and afforded DL-arabinitol. The same reaction-sequence performed on the meso-diepoxide led to a mixture of ribitol and xylitol. 

Mannitol hexanitrate is obtained by nitration of mannitol with mixed nitric and sulfuric acids. Similarly, nitration of sorbitol using mixed acid produces the hexanitrate when the reaction is conducted at 0—3°C and at —10 to —75°C, the main product is sorbitol pentanitrate (117). Xylitol, ribitol, and L-arabinitol are converted to the pentanitrates by fuming nitric acid and acetic anhydride (118). Phosphate esters of sugar alcohols are obtained by the action of phosphorus oxychloride (119) and by alcoholysis of organic phosphates (120). The 1,6-dibenzene sulfonate of D-mannitol is obtained by the action of benzene sulfonyl chloride in pyridine at 0°C (121). To obtain 1,6-dimethanesulfonyl-D-mannitol free from anhydrides and other by-products, after similar sulfonation with methane sulfonyl chloride and pyridine the remaining hydroxyl groups are acetylated with acetic anhydride and the insoluble acetyl derivative is separated, followed by deacetylation with hydrogen chloride in methanol (122). Alkyl sulfate esters of polyhydric alcohols result from the action of sulfur trioxide—trialkyl phosphates as in the reaction of sorbitol at 34—40°C with sulfur trioxide—triethyl phosphate to form sorbitol hexa(ethylsulfate) (123). 

For a long time, this reaction was conducted exclusively with acety-lated nitriles of aldonic acids, and the products obtained were known in general as "aldose-amides. Fischer2 used this reaction to transform tetra-O-acetyl-L-rhamnononitrile into l,l-bis(acetamido)-l,5-dideoxy-L-arabinitol, whose subsequent hydrolysis and oxidation allowed him to determine the configuration of dextro-tartaric acid (L-threaric acid). 

If the nitrile 66 is treated with 5.5% methanolic ammonia, 1,1-bis-(benzamido)-l-deoxy-D-arabinitol (68) is obtained, whereas the same concentration of ammonia in isopropyl alcohol gives60 compound 67. When this reaction was conducted (employing 5.5-8% of ammonia in methanol or isopropyl alcohol) with perbenzoylated D-galactono-nitrile, and with the perbenzoates of D-glucopyranose, D-galacto-... 

C. H. von der Osten, A. Sinskey, C. F. Barbas, R. L. Pederson, Y.-F. Wang, and C.-H. Wong, Use of a recombinant bacterial fructose-1,6-diphosphate aldolase in aldol reactions Preparative syntheses of 1-deoxynojirimycin, 1-deoxymannorjirimycin, 1,4-imino-D-arabinitol, and fago-mine, J. Am. Chem. Soc. 777 3924 (1989). 

The reactions of peroxyl radicals derived from polyhydric alcohols were studied by using flash photolysis of H202 as the radiomimetic system,116 and by various product studies on ethylene glycol,148,149 glycerol,149 erythritol,145 D-arabinitol,149 D-mannitol,148,149 D-glu-citol,145,150,151 myo-inositol,147,152-154 and scyMo-inositol.77... 

The decarbonylation reaction is not confined to aldehydes, but also embraces those compounds that have aldehyde tautomers. Thus, both carbohydrates and allylic alcohols can be decarbonylated. When glucose is allowed to react with frani -[RhCl(CO)(PPh3)2] in A -methylpyrrolidin-2-one, decarbonylation occurs and arabinitol is formed with retention of configuration. The decarbonylation of fructose to arabinitol is complicated by the simultaneous dehydration to furfinyl alcohol, which is the major product. Analogous reactions occur with lower carbohydrates in the limit, glycolaldehyde is decarbonylated to methanol. Aldose derivatives can also be converted to their C i analogues, but the yields are only about half of those obtained with the parent aldoses. Disaccharides usually give better yields. 

Ziegler, T, Straub, A, Effenberger, E, Enzyme-catalyzed reactions. 3. Enzyme-catalyzed s3mthesis of 1-deoxymannojirimycin, 1-deoxynojirimycin and l,4-dideoxy-l,4-imino-D-arabinitol, Angew. Chem., 100, 737-738, 1988. 

When 2-azidoaldehydes are used as substrates in the RAMA-catalyzed aldol reaction with dihydroxy acetone phosphate (DHAP), the azidoketones thus obtained can be reduced into the corresponding primary amines. Subsequent equilibration to imine intermediates, followed by reduction, generates the corresponding pyrrolidines (Scheme 13.16) [22,33]. 1,4-Dideoxy-1,4-imino-D-arabinitol 11 was prepared from azidoacetaldehyde. Both 2R,5R) and 2S,5R)-bis(hydroxymethyl)-(3R,4R)-dihydroxypyrrolidine (12 and 13) were derived from racemic 2-azido-3-hydroxypropanol. The aldol product resulting from kinetic control was converted into the (2R,2R) derivative 12, whereas the product resulting from thermodynamic control gave the... 

Enders and Jegelka [88] have used l,3-dioxan-5-one 122, a protected dihydroxyacetone derivative, to construct enantiomerically pure C5- to C9-deoxycarbohydrates. For example, reaction of 122 with SAMP gives the hydrazone 123, which is deprotonated and alkylated with methyl iodide to yield 124. The monoalkylated hydrazone is then alkylated in the same manner with chloromethyl benzyl ether to form 125. Cleavage of the hydrazone with ozone furnishes the protected ulose 126 (>98% de, >98% ee), which is deprotected to (—)-5-deoxy-L-r/ir o-3-pentulose 127. Reduction of 126 with L-Selectride, followed by deprotection, provides 5-deoxy-D-arabinitol 128 (>95% de, >95% ee) (Scheme 13.46). 

A new class of iso-4 -thionucleosides 171, with the base moiety at the 2 position, was synthesized from D-glucose by the couphng of l,4-anhydro-4-tliio-D-arabinitol 168 with purine and pyrimidine bases using the Mitsunobu reaction. The reaction gave predominantly p isomers 170 a p 1 6), when acetonitrile was used as solvent. The reaction proceed via competition between a direct Sn2 reaction and an episulfonium intermediate 169. 

The iso-4 -thiopurine and pyrimidine L-nucleosides 211 were synthesized from 1,4-thio-L-arabinitol (151) via 3-fluoro derivative 209, which was transformed into 210 by a Mitsunobu reaction. Coupling of 210 with purine and pyrimidine bases by the Mitsunobu reaction, followed by deprotection, gave the desired 211. 

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