L-Arabinitol

Fig. 1. Stmctures of the tetritols (a) erythritol, (b) D-threitol, and (c) L-threitol and the pentitols (d) ribitol, (e) D-arabinitol, (f) L-arabinitol, and (g) xyhtol.

For an alternative approach to naming carbohydrate residues as substituents see 2-Carb-31.2 [which would give the name (II )- or (lS)-L-arabinitol-l-C-yl for the above example, depending on the ligands at the branch point]. 

Useful syntheses of D- and L-lyxose from 1,3-O-benzylidene-D- and L-arabinitol have been achieved through the highly selective oxidation of the primary hydroxyl groups by dimethyl sulfoxide-dicyclohexylcarbodiimide.463 Oxidation of but one of the two (equivalent) hydroxyl groups in 1,3,4,6-tetra-O-benzyl-D-mannitol464 and l,6-di-0-benzyl-2,5-0-methylene-D-mannitol465 was possible with dimethyl sulfoxide-acetic anhydride. 

Pentitol synthesis An asymmetric synthesis of L-arabinitol involves condensation of the (E)-a,fJ-unsaturated ester (2) with the anion of methyl (R)-p-tolyl sulfoxide (1). The resulting p-keto sulfoxide (3) is reduced stereoselectively by ZnCl2/DIBAH (13, 115-116) to 4. Osmylation of 4 with (CH,)3NO and a catalytic amount of 0s04 (13, 224-225) yields essentially a single triol (5). Finally, a Pum-merer rearrangement of the sulfoxide followed by reduction of an intermediate... 

Keywords a,co-Alkanediamines, l,4 3,6-Dianhydrohexitols, Aldaric acids, Aldo-nolactones, Aminoalditols, o-Glucitol, Diaminoalditols, D-Mannitol, D-Xyhtol application, Erythritols, Isoidide, Isomannide, Isosorbide, L-Arabinitol, Lipase-catalysis, Polyamides, Polycarbonates, Polyesteramides, Polyesters, Polyethers, Polyureas, Polyurethanes, Super-acid, Tartaric acids... 

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. 

The hydrolytic degradation of a series of homo- and copolyesters analogous to PET and PEI based on the mentioned L-arabinitol, xylitol, o-mannitol, and galactitol were relatively fast at temperatures 10°C above their respective Tg [53]. 

Galbis and Munoz-Guerra et al. used the secondary G-protected L-threitol, L-arabinitol and xylitol (5-12) as monomers for the preparation of a series of linear [/M, ]-type polyurethanes 97 and 98 by polycondensation in solution with... 

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]. 

The synthesis of l,5-dideoxy-l,5-imino-L-arabinitol (13), a derivative of (5) lacking the hydroxymethyl side chain at C-5 was reported [49]. This compound did not exhibit any appreciable activity with imspecified galactosidases. 

Cisplatin is a widely used chemotherapeutic agent against various human cancers. Cisplatin-like complexes of free and partially protected 1-amino-1,2,5-trideoxy-2,5-imino-L-arabinitol (98) and (99) were recently synthesized and found to exhibit high cytotoxicities against a range of human cancer cell lines [181]. 

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. 

The formation of 34 was explained by a rearrangement of 33 by way of a benzoxonium intermediate the ion is attacked at the less-hindered, C-5 position, to give a 5-deoxy-5-iodo derivative. The structure of 34 was confirmed by its reduction to 4-0-benzoyl-l,5-dideoxy-2,3-0-iso-propylidene-L-arabinitol. 

Cleavage of the dithioacetal groups from the products, followed by reduction of the resultant carbonyl derivatives (46, 49, 52) with sodium borohydride leads,68 with the three compounds (45, 48, and 51), to 1,4-anhydro-L-ribitol (2,5-anhydro-D-ribitol) (47), 1,4-anhydro-L-xylitol (2,5-anhydro-D-xylitol) (50), and 1,4-anhydro-D-arabinitol (2,5-anhydro-D-lyxitol) (53), identified by comparison with their enantiomorphs, 1,4-anhydro-D-ribitol,69 1,4-anhydro-D-xylitol,70 and 1,4-anhydro-L-arabinitol. 71... 

Anhydropentitols have also been synthesized by the reductive desulfurization of 1-thioglycofuranosides.1 Syrupy 1,4-anhydro-L-arabinitol, characterized as the tris(p-nitrobenzoate), and crystalline 1,4-anhydro-D-ribitol14 have been obtained by reduction of the cor-... 

Several 2,5-anhydropentitols have been synthesized from suitably protected pentoses by standard procedures (see also, Ref. lb). Thus, ethyl 5-O-p-tolylsulfonyl-a-L-arabinofuranoside (11) was converted17 into the corresponding 2,5-anhydride (12) by treatment with metha-nolic sodium methoxide. The product was hydrolyzed, and the resulting 2,5-anhydro-L-arabinose was hydrogenated in the presence of Raney nickel to give 2,5-anhydro-L-arabinitol (13) as a syrup. 

Defaye19 called attention to the fact that the 2,5-anhydro-tri-0-(p-nitrobenzoyl)-D-lyxitol that he prepared is the enantiomorph of Barker and Fletcher s 1,4-anhydro-tri-0-(p-nitrobenzoyl)-L-arabinitol.l4alditol anhydrides derived, without Walden inversion, from two configurationally different sugars have been shown experimentally to possess the same, although enantiomorphic, configuration. 

D,L-Arabinitol can be prepared by the action of hydrogen peroxide in the presence of formic acid on divinyl carbinol (36) and, together with ribitol (Fig. ld),fromD -erythron-4-pentyne-l,2 -triol,HOCH2CHOHCHOHC=CH (37). 

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). 

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