Sugars alkali

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. 

Only the racemic form of this acid is obtained from the sugar-alkali reaction. As in the formation of lactic acid, a non-asymmetric enediol is an intermediate in its production (see Section III), and hence the racemate is the sole representative of the four-carbon metasaccharinic acid class. 

This recently discovered, racemic acid of the five-carbon aeries is only the third example of an isosaccharinic acid to be identified as a product of the sugar-alkali reaction. The other examples are the a- and /3-D-isosac-charinic acids of the six-carbon aeries (see pages 48 and 52). 

The best evidence for the formation of 8 -D-isosaccharinic acid in the sugar-alkali reaction is the recent observation" that treatment of lactose, maltose, or 4-0-methyl-D-glucose with lime-water at room temperature provides initially a mixture of saccharinic acids consisting almost exclusively of a -D-isosaccharinic acid plus an acid with the properties of Nef s /3 -D-isosaccharinic acid [brucine salt, m. p. 185 to 210 (dec.), [a]n - 20 to —22° lactone, [ajp -)-6 to - -8.5°]. An experimental proof that this substance possesses the isosaccharinic acid structure would provide the necessary evidence that it is, indeed, the epimer of a -D-isosaccharinic acid. 

Dihydroxybutanoic acid, a 3-deoxytetronic acid, is the only theoretically possible four-carbon metasaccharinic acid it was isolated by Nef in the dl form (Ilab) in the course of his work on the action of sodium hydroxide on D-arabinose. It therefore constitutes the only four-carbon saccharinic acid isolated to date from a sugar-alkali reaction. Resolution of this on acid (Ilab) was accomplished by Nef, who showed that the dextrorotatory acid (Ila) upon oxidation gave rise to 2-deoxy-L-f/Z2/cero-tetraric acid [(-)-)-d-malic acid XV]. During the course of this work, several derivatives of the L and DL saccharinic acids (lib and Ilab) were prepared, but only the brucine salt of the d acid (Ila) was reported. 

H02C(CH2)2C02H. Colourless prisms m.p. 182 C, b.p. 235°C. Occurs in amber, algae, lichens, sugar cane, beets and other plants, and is formed during the fermentation of sugar, tartrates, malates and other substances by a variety of yeasts, moulds and bacteria. Manufactured by the catalytic reduction of maleic acid or by heating 1,2-dicyanoethane with acids or alkalis. Forms an anhydride when heated at 235°C. Forms both acid and neutral salts and esters. Used in the manufacture of succinic anhydride and of polyesters with polyols. 

Dimethyl sulphate is of particular value for the methylation of phenols and sugars. The phenol is dissolved in a slight excess of sodium hydroxide solution, the theoretical quantity of dimethyl sulphate is added, and the mixture is heated on a water bath and shaken or stirred mechanically (compare Section IV, 104). Under these conditions only one of the methyl groups is utilised the methyl hydrogen sulphate formed in the reaction reacts with the alkali present. -... 

The following are some of the typical industrial applications for liquid-phase carbon adsorption. Generally liquid-phase carbon adsorbents are used to decolorize or purify liquids, solutions, and liquefiable materials such as waxes. Specific industrial applications include the decolorization of sugar syrups the removal of sulfurous, phenolic, and hydrocarbon contaminants from wastewater the purification of various aqueous solutions of acids, alkalies, amines, glycols, salts, gelatin, vinegar, fruit juices, pectin, glycerol, and alcoholic spirits dechlorination the removal of... 

Nucleosides are much more water-soluble than the free bases because of the hydrophilicity of the sugar moiety. Like glycosides (see Chapter 7), nucleosides are relatively stable in alkali. Pyrimidine nucleosides are also resistant to acid hydrolysis, but purine nucleosides are easily hydrolyzed in acid to yield the free base and pentose. 

Explds at 60° after 13 sec in a sealed glass tube (Ref 4). Explds spontaneously when frozen and then thawed. Compd is a violent expl, extremely sensitive to impact or friction. It Jalso explds on exposure to strong light (sunlight or diffused), or when in contact with P, As, ozone, fused alkalies, and organic matter such as turpentine rubber, but not with sugar or resins. Metals strong acids do not cause it to expld,... 

Exhaustive oxidation of sulphones to sulphate using a mixture of potassium chlorate, sodium peroxide and sugar in a bomb has also been recommended220. This procedure is known as the Parr method and produces a mixture of soluble alkali sulphates. 

Amino-sugars and Related Compounds. VI. The Action of Alkali on Some Benzyloxycarbonyl-amino Derivatives, A. B. Foster, M. Stacey, and S. V. Vardheim, Acta Chem. Scand., 13 (1959) 281-288. 

Sucrose degrades in acid far more easily than in alkali, and invert sugar (the product of acid hydrolysis) is far more reactive in alkali than in acid. 

Because alkali degradation of sucrose does not result in inversion products, in slightly alkaline solution (pH < 8.5), the loss of sucrose to invert sugar (glucose + fructose) is a consequence of the acid hydrolysis mechanism, which provides D-glucose and D-fructose for further alkaline degradation. 

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