Saccharinic acids from

Figure 11.5 Formation of methylated saccharinic acids from glucose and cellulose, and methylated deoxyglucaric acid from glucuronic acid [66,681...

A. Ishizu, B. Lindberg, and O. Theander, Saccharinic acids from D-xylose and D-fructose, Acta Chem. Scand., 21 (1967) 424 132. 

In support of his contention that /3 -D-isosaccharinic acid is present in the hexose-alkali reaction mixture, Nef also cited certain observations of Kiliani and Eisenlohr, who oxidized (with nitric acid) the residue obtained, after substantial removal of a -D-isosaccharinic acid and the meta-saccharinic acids, from the lactose-alkali reaction mixture. Among the products identified was the tribasic acid, (H02C)2C(0H)—CHj—CHOH— CO2H, previously obtained by a similar oxidation of a -D-isosaccharinic acid (see page 50). Nef concluded that the tribasic acid must in this instance have arisen from j3 -D-isosaccharinic acid. This conclusion ignores, however, the experimental demonstration by Kiliani and Eisenlohr that the residue subjected to oxidation had still contained a small proportion of a -D-isosaccharinic acid, isolable as the slightly soluble calcium salt. 

An experimental demonstration that the Nef mechanism for the initial conversion of a sugar by alkali to the a-dicarbonyl structure is not acceptable was provided by a study of the action of alkali on 2 hydroxy-3-meth-oxy-3-phenylpropiophenone. Nicolet observed that the products in this case are 2,3-diphenyllactic acid and methanol. This conversion, which is completely analogous to the formation of a saccharinic acid from a reducing sugar, demonstrated clearly that carbon-oxygen cleavage occurs at the /3-carbon atom, rather than at the a-carbon atom, with respect to the carbonyl group. 

In publishing this definition, Glattfeld and Sherman were careful to state that it was purely formal and was not to be considered a statement of their idea as to the theory underlying the actual formation of the saccharinic acids from the sugars. Whether or not these acids are really produced by such a direct internal oxidation-reduction as is implied in the definition, they may nevertheless be defined as the products of such a reaction. 

In 1909, Kay reported the preparation of a small quantity of the levorotatory potassium salt of this saccharinic acid from d-a-methylisoserine (XLV). Treatment of d-a-methylisoserine (XLV) with nitrosyl bromide gave 3-bromo-2-hydroxy-2-methylpropanoic acid (XLVI). The latter, on... 

This work on the isomerization of D-glucose was responsible for the intensive interest which Sowden developed in saccharinic acids. From Schaffer s work, Sowden learned of the relative ease of isolation of saccharinic acids from isoraerized solutions. As a result, Miss Dorothy J. Kuenne was started on an investigation of the mechanism of formation of saccharinic acids, and the first report of this work was published in 1953. In the next few years, six additional investigations were reported in which specially labeled sugars played an important role. To Volume 12 of this Series, Sowden contributed a review on saccharinic acids which presents a clear and impressive account of the state of this complex area of sugar chemistry. 

There are some components which may be regarded as anionic trash that are beneficial to rosin sizing such as saccharinic acids from alkaline pulping and hemicelluloses from unbleached pulps. These can form complexes with AP+ ions and produce rosin size precipitates of lower melting or sintering points. This promotes more efficient sizing. 

Dehydration appears to be facilitated by the presence of a substituent methoxy or glycosyl group (106). The distribution of activity in the metasaccharinic acid from D-galactose-l-C is in agreement with the Nef-Isbell mechanism (107). However, a distribution of between carbon atom 2 and the methyl group (in the ratio of 3 2) found in the saccharinic acid from D-mannose-l-C demands another or additional explanation. A recombination of fragments seems necessary to account for the appearance of at the tertiary position (107). 

Fiqure 4.48 Formation of saccharinic acids from glucose and fructose. 

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