Alditols 1-deoxy-, preparation

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. 

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-... 

The D-glucose/D-mannose system, the most convenient for such model studies, was chosen again however, with the necessary modifications. While 2-C-(hy-droxymethyl)-D-mannose (16 c X = CH2OH, Z = H, n = 2, Scheme 8) is conveniently available via aldolization of 2,3 5,6-di-0-isopropylidene-D-mannose with formaldehyde [50], this is not the case for 2-C-(hydroxymethyl)-D-glucose (15 d X = H, Z = CH2OH, n = 2y Scheme 8). Therefore, both 2-C-(hydroxymethyl) aldoses were prepared by the addition of nitromethane to D-fructose (17) followed by transformation of the intermediates, epimeric l-deoxy-2-C-(hydroxymethyl) alditol-1-nitronates 18 and 19 by the Nef reaction (Scheme 9) [51]. In spite of its apparent simplicity, it was the first synthesis of 2-C-(hydroxymethyl)aldoses using this sequence. Thus, a 1 1 mixture of the branched-chain aldoses 15 d and 16c was obtained in 18% yield. 

Subsequently, isomerases from Aerobacter aerogenes strains which also converted L-xylose (110, Scheme 33) were purified [91,92] and the inducible enzymes from two other E. coli strains were compared [93]. It was demonstrated that both preparations were tetramers with masses around 350 kDa and were active with L-fucose (15) and D-arabinose (13). However, this was not the case for the other aldopentoses and hexoses probed such as L-arabinose (24), l-rhamnose (26), D-xylose (18), D-ribose (20), d- (17) or L-glucose (58), d- (44) or L-mannose (111), D-galactose (57) or D-fucose (6-deoxy-D-galactose, 112). Both enzymes were inhibited by alditols related to their natural substrates, exhibited their optimal catalytic activities in alkaline media, and were stimulated by the presence of Mn as well as Co but strongly inhibited by Cd. ... 

Amino-Alditols. - Aldose oximes, e.p... of mannose and arabinose, can be reduced electrochemically to 1-aminoalditols glucose oxime reacted differently, because, it is proposed, of its strong tendency to cyclize to an N-glucosyl hydroxylamine derivative. l-Amino-2-acetamido-1,2-dideoxy-D-alditols have been prepared by sodium cyano-borohydride reduction of 2-acetamido-2-deoxy-glycosylamines (D-Glc, D-Man, and D- lc-D-Glc).6-(5-deoxy-D-ribit-5-yl)amino-uracil has been condensed with 2-chloro-4-hydroxybenzaldehyde to give a flavin derivative which was further elaborated to Redox Coenzyme Factor 420. ... 

A combined enzymatic/chemical synthesis of imino-alditols used fructose 1,6-diphosphate aldolase to generate 6-azido-ketohexoses (as outlined in Scheme 4) which could be catalytically reduced to deoxynojirimycin and deoxymannojirimycin. By use of appropriate azido-aldehydes, fagomine(15) and 1,4-dideoxy-l,4-imino-D-arabinitol (16) were similarly prepared. Microbial epimerization of 1-deoxy-... 

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. ... 

Several imino-alditols have been prepared from non-carbohydrate sources. 2,S-Dideoxy-2,S-imino-D-mannitol has been synthesized from a pyroglutamic acid derivative (see Vol. 27, p. 209, ref. 59 for the use of pyroglutamic acid in the synthesis of other imino-alditols), and 1-deoxy-L-allonojirimycin has been made from a protected L-serine derivative. A protected D-serine aldehyde provided access to a l,2,4-trideoxy-l,4-imino-D-eryrAro-pentitol derivative for incorporation into DNA, and reduction of the minor natural amino acid, 4-L-hydroxyproline, gave l,3,4-trideoxy-l,4-imino-D-eryrAro-pentitol which, after Af-acylation with a fluorescent probe, was incorporated into oligonucleotides. ... 

Asymmetric syntheses of 6-deoxy-D-allonojirimycin and D-fuconojirimycin as well as their 1-deoxy analogues by cylcloaddition of a diene with 1-C-nitroso-D-mannofuranosyl chloride in a similar way to that described in Vol. 27, p. 207, ref. 46 for the preparation of racemic imino-alditols, have been described. (See also... 

Dihydrocyclopentene derivatives (from cyclopentadiene) after kinetic resolution with a lipase are useful precursors for the synthesis of 1-deoxy-D-nojirimycin, and benzene cis-diol (from benzene by microbial oxidation) has been used as a precursor to 1-deoxy-D-galactonojirimycin and bicyclic derivative 59. The preparation of imino-alditol derivatives in which the imino nitrogen atom is part of a fused tetrazole ring is mentioned in Chapter 10 and the synthesis of imino-lactams is covered in Chapters 10 and 16. 

Amino-l-deoxy-alditol derivatives have been prepared conventionally from glucose and reducing oligosaccharides to provide link-32 33... 

The preparations of derivatives of 3-0-(a-D-glucopyranosyl)-deoxymannojirimycin in which the imino-alditol portion has been modified to analogous 2-deoxy, 2-O-methyl, 4-deoxy, 4-O-methyl, 6-deoxy, 6-O-methyl and i f-alkyl groups, have been described and tested for glycosidase activity/ ... 

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