Deoxyaldonic acids

Deamination of 2-amino-2-deoxyaldonic acids with nitrous acid has been shown to give 2,5-anhydroaldonic acids with overall retention of the configuration of C-2. The reaction parallels the deamination, with nitrous acid, of a-amino acids that leads to a-hydroxy acids with retention of configuration.19,29 Thus, the formation of 2,5-anhydro-D-gluconic acid27 (15) from 2-amino-2-deoxy-D-gluconic acid (14) has... 

Simple syntheses of suitable monomers for nylon 5 and nylon 6 analogs, such as 5-amino-5-deoxyaldonic and 6-amino-6-deoxyaldonic acids (51, 54), has been achieved starting from unprotected o-pentono- and hexono-1,4-lactones [68, 69]. Saponification of 5- or 6-azido-D-aldonolactones ribo-, arabino-, xylo-, galacto-, manno-, compound types 49 and 52) provided the corresponding 5- or 6-azido-aldonic acid sodium salts (50, 53). A catalytic hydrogenation after or before treatment with acidic resin afforded compounds 51 and 54 in excellent overall yields (Scheme 16). 

Saccharinic acids are (monocarboxylic) deoxyaldonic acids having the general formula CnH2 0 . Of interest here are only those that can be formed from 1,2- or 2,3-enediols by /3-elimination followed by benzilic acid rearrangement. They are of three types metasaccharinic, I, saccharinic, II, and isosaccharinic, III. The C-2 epimers are distinguished as a and /3. ... 

Anhydroaldonate derivatives are formed in good yield when 2-amino-2-deoxyaldonic acids are deaminated. Thus, deamination of 2-amino-2-deoxy-L-(and D-)gluconic acid was used to form the tetra-... 

The rates of hydrolysis of the lactones depend on the parent structure for instance, the 1,4-lactone of D-mannonic acid is more stable than that of D-gluconic acid, and the 1,4-lactones of 2-deoxyaldonic acids are more stable than the corresponding aldonolactones. The final attainment of equilibrium between free aldonic acids and their lactones is reached only after many days at room temperature it is, however, accelerated by the presence of strong acids and by heating. A detailed discussion of the formation and hydrolysis of aldonolactones is available in a review by Shafizadeh,59 and the conformations and stabilities of aldonolactones have been discussed by Lemieux.60 Detailed analyses of D-glucono-1,5-lactone and other lactones have been reported.61 13C NMR spectroscopy proved to be a convenient method for monitoring the equilibria.62... 

Treatment with silver oxide in water causes these a-diazoketones to undergo the Wolff rearrangement, yielding 2-deoxyaldonic acids (Scheme 6).95... 

The 3-deoxyaldonic acids (metasaccharinic acids) arise by alkaline treatment of monosaccharides, especially those substituted at C-3.288 They have also been obtained from (1 - 3)-linked oligo- and polysaccharides. The most common ones are 3-deoxy-D-n Z>o-hexonic acid (a-D-glucometasaccharinic acid, 109) and 3-deoxy-o-arabino-hexonic acid (jS-D-glucometasaccharinic acid, 110), which can most conveniently be... 

Selective oxidation at C-2 of 3-deoxyaldonic acids by the action of sodium perchlorate in the presence of vanadium pentaoxide has been used for the preparation of deoxyketoaldonic acids, although low yields of pure compounds are obtained. The necessary 3-deoxyaldonic acids may be prepared by a cyanohydrin chain-extension reaction. Several syntheses have been reported for 3-deoxy-D-araZu rao-hept-2-ulosonic acid starting from 2-deoxy-D-arabino hexose 310,311 DAHP (122) has also been similarly prepared.312... 

In a third general approach, 2-keto-3-deoxyaldonic acids are prepared from 2-enonolactones. These precursors are readily prepared in good yield by /1-elimination reactions on the protected lactones.37 Starting from... 

G. Peterson, Mass spectrometry of aldonic and deoxyaldonic acids as trimethylsilyl derivatives, Tetrahedron, 26 (1970) 3413-3428. 

G. Limberg and J. Thiem, -Elimination of protected aldono-1,4-lactones as a general approach to the synthesis of 2-keto-3-deoxyaldonic acids containing four to six carbon atoms, Carbohydr. Res., 275 (1995) 107-115. 

In the case of 2-deoxyaldoses, where no hydroxyl group is present at C-2, the m-hyd roxy-hydroxyperoxide cleavage is not possible and a different pathway affords the 2-deoxyaldonic acids,103 as shown in Scheme 18. 

Disaccharides and polysaccharides are also oxidized by the same degradative oxidation at first they react rapidly then, when the point of branching is reached, they react much more slowly. When subjected to similar oxidations, ascorbic acid affords threonic acid and oxalic acid, and 2-deoxy sugars yield 2-deoxyaldonic acids and lower alditols. 

Furthermore, the sterically unfavorable, seven-membered lactams are readily obtainable from the 6-amino-6-deoxyaldonic acids. Thus, on treatment with alkali at room temperature, 6-amino-6-deoxy-L-gulono-l,4-lactone hydrochloride (157) gives L-gulono-l,6-lactam... 

Due to the growing interest in organic acidurias, urinary acids have been studied at some length. Although many of the acids present have been identified, many have not, often because of inadequate GC resolution or poor extraction. A series of aldonic and deoxyaldonic acids were recently detected [358] using a DEAE extraction method [359]. The greater sensitivity which is possible by more extensive fractionation has... 

Three structurally isomeric forms have been established for the six-carbon saccharinic acids. In the order of their discovery, these are the sac-charinic or 2-C -methylpentonic acids, the isosaccharinic or 3-deoxy-2-C -(hydroxymethyl)-pentonic acids, and the metasaccharinic or 3-deoxy-hexonic acids. Although none of these six-carbon, deoxyaldonic acids has been crystallized, six are known in the form of crystalline lactones (saccharins). All the possible metasaccharinic acids of less than six-carbon content have been obtained, in the form of crystalline derivatives, by the sugar-alkali reaction. Only one example of a branched-chain deoxyaldonic acid (the racemic, five-carbon isosaccharinic acid) of other than six-carbon content has been so obtained. The formation of saccharinic acids containing more than six carbon atoms remains to be explored. 

Zhdanov. Y.A.. Uzlova. L.A., and Glebova, Z.I., The Arbuzov reaction of higher 2-deoxyaldonic acid chlorides, Dokl. Akad. Nauk SSSR, Ser Khim., 255, 870, 1980 Chem. Abstr., 95, 7660, 1981. 

Deoxyaldonic acids, also, suffer /3-elimination in basic solution to give compounds which fall within this class the acid derived by oxidation of the naturally occurring cladinose, a 2,6-dideoxy-3-C-methyl-3-0-methyl-hexose, gave a lactone believed to be 2,3,6-trideoxy-3-C-methyl-D-eryi/iro-hex-2-enono-l,4-lactone (83). Other acyclic, unsaturated acids (see p. 130) could readily give rise to analogous lactones. 

There have been reports on new routes to 2-amino-2-deoxyaldonic acids (polyhydroxylated a-aminoacids). One approach to compounds of this type is illustrated by the... 

The action of HBr on the diazo compound is similar to that of acetic acid, and a 1-bromo keto acetate is formed. Silver oxide causes a rearrangement to a 2-deoxyaldonic acid 35),... 

For the preparation of the 2-amino-2-deoxyaldonic acids, the common bromine oxidation does not give good yields, and mercuric oxide is the preferred oxidant. By the use of mercuric oxide, glucosaminic acid was obtained in yields of 62 % 302). Lactone formation does not occur in solution, unless the amino group is substituted. Epimerization of the acid occurs in pyridine solution at 100 , and the corresponding mannose derivative is formed 303). Numerous degradative oxidations have been studied (S04) ... 

Deoxyaldonic acids result in good yield from the treatment of aldose 2-sulphonates with aqueous lead (II) hydroxide under nitro-... 

Sialic acids were reported to occur in all species of vertebrates and in certain invertebrates as well (Warren, 1963a), NANA is present in some strains of E, coli and other bacteria as a homopolymer, of which colominic acid is one example (Barry and Goebel, 1957 Barry et al., 1962 Watson et al., 1958 Liu et aL, 1971). However, it is lacking in other bacteria (Barry, 1959 Barry et aL, 1%3 Jann, 1969). Earlier claims for the presence of sialic acid in plant extracts have been disputed (Cabezas and Feo, 1969) since the positive test with thiobarbituric acid could not be duplicated by other colorimetric assays. Gielen (1%8) demonstrated that the color-producing substances in certain plant hydrolysates were 2-keto-3-deoxyaldonic acids rather than sialic acid. To date there has been no convincing evidence for the presence of sialic acid in plants. 

As with other colorimetric methods, the thiobarbituric assay is subject to interference by a number of foreign substances in biological materials. In addition to the problem with 2-keto-3-deoxyaldonic acids... 

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