Alditols 2.5- anhydro-, preparation

Anhydro-alditols - The preparations of polyesters based on l,4 3,6-di-anhydro-D-glucitol and -o-mannitol with succinyl-, glutaryl- and adipoyl-dichlor-ides have been reported. Also reported have been the syntheses of poly(1 6)-2,5-anhydro-D-glucitol and its 3,4-di-0-alkylated derivatives by Lewis acid induced polymerization of 3,4-di-0-alkyl-l,2 5,6-dianhydro-D-mannitol base induced polymerization of l,2 5,6-dianhydro-3,4-di-0-methyl- or 3,4-di-O-iso-propylidene-D-mannitol base induced polymerization of l,2 5,6-dianhydro-3,4-di-O-pentyl- or di-O-decyl-o-mannitol and base induced polymerization of l,2 5,6-dianhydro-3,4-di-0-methyl-L-iditol. The solubilities of these 3,4-di-O-alkylated and deprotected polymers in aqueous and organic media were studied. Further, it has been reported that 2,5-anhydro-3,4-di-0-methyl-D-glucitol linked 1,6 to silica gel was useful for the optical resolution of amines and amino acid salts. ... 

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. 

The synthesis of an alditol having a 4-membered (oxetane) ring was first reported by Ustyuzhanin and coworkers,50 who prepared 1,3-anhydro-5,6-di-0-methyl-2,4-0-methylene-D-glucitol by saponification of the 1-p-toluenesulfonate of the corresponding derivative of D-... 

Attempts to use 4,5,7-tri-0-acetyl-2,6-anhydro-l,3-dideoxy-l-iodo-D-giuco-heptitol for x-ray analysis were unsuccessful, because only twinned crystals could be prepared. Use of die deacetylated p-toluenesulfonate, namely, 2,6-anhydro-3-deoxy-l-0-p-tolylsulfonyl-D-gl co-heptitol, and of the parent alditol, 2,6-anhydro-3-deoxy-D-glaco-hepti-tol, was unsuccessful because no atom of sufficient electron density was present. 

The preparation of a number of a,b>-dimethanesuIfonates of alditols has been described. For example, by treating l,2 5,6-dianhydro-3,4-di-O-isopropylidene-D-mannitol with methanesulfonic acid, 1,6-di-0-(methylsulfonyl)-D-mannitol was formed. It is noteworthy that treatment of l,2-anhydro-3-deoxy-DL-glycerol with p-toluenesulfonic acid gave 3-deoxy-l-O-p-tolylsulfonyl-DL-glycerol and 3-deoxy-2-O-p-tolylsulfonyl-DL-glycerol. 

Substrates of this type were utilized for the synthesis of alditols. Schneider and co-workers prepared from trans and cis 2-buten-1,4-diols 2,3-anhydro-DL-erythritol (54) and -threitol (55) by direct epoxidation with peroxybenzoic acid. This method of epoxide formation failed in the case of 2 ,4 -hexadiene-l,6-diol from the 2Z,4Z isomer the corresponding diepoxide (57) was obtained in a 2% yield only. However, from 1,6-dibromo-and 1,6-dibenzyloxycarbonyloxy-2 ,4 -hexadienes the corresponding derivatives of 2,3 4,5-dianhydro-DL-gal-actitol (56) could be obtained in moderate yields. Compounds of this type are active against some forms of sarcoma. 

Fleet and co-workers have prepared tetrahydrofuran azido-acids such as 55 and 56 and demonstrated their use as building blocks for peptidomimetics. The synthesis of l,4-anhydro-3,6-diazido-4-thio-alditol derivatives is detailed in Chapter 11. ... 

In connection with the analysis of ollgo- and polysaccharides by the permethylation - "ionic hydrogenation" procedure, a series of partially methylated anhydro-D-alditol acetates has been prepared by reductive cleavage of permethyl and partially methylated methyl glycosides and a library of capillary g.c. retention times and e.l.- and c.i.-m.s. data compiled. The usefulness of this data was demonstrated in the analysis of a microgram quantity of a... 

Anhydro Alditols. - A standard procedure has been used to convert the glucosamine derivative (13) to its 1,2-dideoxy analogue, and then to prepare the glycoprotein 1-deoxy-MDP and some other lipo-... 

Alditols, particularly glycerol (I), ethylene glycol, sorbitol, and D-manni-tol, have widespread commercial applications, frequently as a result of their hygroscopic properties. The organic monoesters, particularly of long-chain fatty acids, may have surface-active properties which make them of interest as emulsifiers, but the usual conditions of commercial esterification produce anhydro derivatives simultaneously (Chapter VII). Nitrate esters are important as explosives and as pharmaceuticals. The acetal derivatives (Chapter IV) have been extensively prepared and studied, but as yet have found no practical application. 

Catalytic reduction of various sugar derivatives, with the retention of the sugar ring, may be employed to prepare anhydro alditols. 

Reductive desulfurization has been extended to the appropriate ethyl 1-xanthate or ethyl, phenyl, and naphthyl 1-thioglycosides to prepare the 1,5-anhydro derivatives of D-glucitol, D-mannitol, galactitol, cellobiitol, gentiobiitol, maltitol, lactitol, D-arabitol, ribitol, and xylitol (56). When a 1-thioaldofuranoside is reductively desulfurized, the product is the corresponding 1,4-anhydro alditol (57). 

The most convenient reductive method for preparing anhydro alditols involves the reaction of the acetylated or benzoylated glycosyl halides with lithium aluminum hydride. The aldopyranosyl halides (III) yield 1,5-an-hydro alditols in good yield, whereas the furanosyl derivatives (IV) provide... 

AnhydrO Alditols- An improved preparation of the four epoxybutanediol acetonides 24 (RR,RS,SR or SS) from L-ascorbic acid or D-isoascorbic acid (cf. Vol. 24, p. 195, ref. 16) has been described. The conversion of these isomers into enantiomerically pure glyceraldehyde derivatives, threose/erythrose derivatives or 2,3-anhydro threose/erythrose derivatives by initial treatment of 24 with various organometallic reagents is also reported. These latter compounds are useful building blocks for the synthesis of acyclic oxygenated fatty acid metabolites. 

D-Glucitol is converted to a mixture of 1,4-anhydro-D-glucitol, 2,5-anhydro-L-iditol, 2,5-anhydro-D-mannitol and l,4 3,6-dianhydro-D-glucitol on treatment with hydrogen in the presence of a Cu-Ru catalyst. Reactions of other alditols with bimetallic catalysts are described. The preparations of three stereoisomers (exo, endo endo, exo endo, endo) of the known Chem. Abstr., 1991, 115, 136 644) dianhydro nitrate derivative 27 (exo, exo form) have been reported and the enzymatic preparations of l,4 3,6-dianhydro-D-glucitol mono acetates is mentioned in Chapter 7. 

Anhydro-Alditols. - 2-And/or 3-methyl or ethyl ethers of methyl f-D-glucopyranoside have been used to prepare a series of 2- and/or 3- and/or 6-methyl and/or ethyl ethers of 1,5-anhydro-D-glpcitol, which can also be reductive cleavage products of partially methylated or ethylated celluloses. 

Anhvdro-Alditols. - The synthesis of a whole range of 1,5- and 1,4-anhydro-alditols and their inhibitory effects against glycosidases have been reported. The preparation of 2,5-anhydro-3-deoxy-D-araWno-hexitol by hydrogenation of 2,5 3,4-dianhydro-D-allitol over Pearlman s catalyst has been described. The selective chlorination of pentitols to afford l,5-dichloro-l,5-dideoxy derivatives as well as mono- and di-chloro-l,4-anhydro derivatives has been reported. ... 

The contribution to the c.d. of pair interaction between acetyl groups in acetyl derivatives of 1,5-anhydro-alditols accounts for the observed signal, and allows their stereochemistry to be deducedf 1.3 Branched-Chain Alditols.- Doubly branched alditols (19) have been prepared (as sections of erythronolide B) by cuprous cyanide... 

Anhydro-Alditols.-The uses of l,4 3,6-dianhydroglucitoI and -dianhydromannitol to prepare high molecular weight polyesters, polyurethanes and polycarbonates has been reported. ... 

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