Sucrose condensation products

Alkaline Degradation. At high pH, sucrose is relatively stable however, prolonged exposure to strong alkaU and heat converts sucrose to a mixture of organic acids (mainly lactate), ketones, and cycHc condensation products. The mechanism of alkaline degradation is uncertain however, initial formation of glucose and fructose apparendy does not occur (31). In aqueous solutions, sucrose is most stable at —pH 9.0. 

The hexoses that are the initial products of acid hydrolysis of sucrose (1) react at el vated temperature under the influence of acids to yield furfural derivatives (2). Thed condense, for example, with the phenols to yield triarylmethanes (3), these react furthei by oxidizing to yield colored quinoid derivatives (2, 4). Polyhydric phenols, e. g. resorj cinol, on the other hand, yield condensation products of Types 5 and 6 [2],... 

Disaccharides are condensation products of two monosaccharide units. Examples are maltose and sucrose. 

The true analogue of sucrose, 1-thiosucrose (98) was obtained using an acid-catalysed condensation involving the two synthons (10 b) and (97) (Scheme 28) [19]. It is worthy of note that the classical method failed to give any condensation products. 

When sucrose is heated above its point of fusion it becomes coloured and ends by becoming transformed into a brown mass, caramel. Glucose also yields a like product. Caramel is evidently a carbohydrate of high molecular weight and a condensation product of sucrose or glucose. From cryoscopic determinations and analysis of its barium compound its formula has been given as Ci26Hx8808o. 

STRUCTURAL IDENTIFICATION OF THE CONDENSATION PRODUCT OF SUCROSE WITH ORGANOSTANNANE DIHALIDES... 

This paper concentrates on the identification of the structural unit of the condensation product between sucrose and organo-stannane. As in the ease of dextran modification, the product contains a mixture of units including those depicted as to 7. 

Further, Figure 1 contains a companion infrared spectrum of the condensation product of dibutyltin dichloride and dextran. This spectrum appears strikingly similar to that of the product derived from sucrose. This is reasonable since the major structural difference is the presence of five membered rings in sucrose compared to only six membered rings present in dextran. 

Table 1. Major ion fragments for the gasses derived from the thermal degradation of the condensation product of sucrose and diphenyltin dichloride...

Mass spectral results for thermal pyrolysis of the condensation product of sucrose and dibutyltin dlchloride are given in Table 3. Again no ion masses are found attributable to tin or a tin-containing moiety consistent with tin remaining in the residue. For both spectra, the presence of only small amounts of m/e=35,37 derived from chloride are present consistent with a high amount of crosslinking. 

Table 2. Biological assays for condensation products derived from organostannane dihalides and sucrose. 

The treatment of sucrose with anhydrous HF89 results in the formation of a complex mixture of pseudooligo- and poly-saccharides up to dp 14, which were detected by fast-atom-bombardment mass spectrometry (FABMS). Some of the smaller products were isolated and identified by comparison with the known compounds prepared86 88 a-D-Fru/-1,2 2,1 -p-D-Fru/j (1), either free or variously glucosylated, was a major product, and this is in accord with the known stability of the compound. The mechanism of formation of the products in the case of sucrose involves preliminary condensation of two fructose residues. The resultant dianhydride is then glucosylated by glucopyranosyl cation.89 The characterization of this type of compound was an important step because it has permitted an increased understanding of the chemical nature of caramels. 

Although the above condensations definitely failed to yield sucrose octaacetate, Irvine and his collaborators showed that they did produce, in addition to uncrystallized products, some D-glucose pentaacetate, some... 

In 1930, Blagoveschenski claimed66 the synthesis of raffinose by the condensing action of almond emulsin on a mixture of sucrose and D-galac-tose. The small amount of product (which had [o]d + 95.66°) was hydrolyzed by emulsin, and may have been at least partly raffinose, but the work should be repeated, using a more definitive test for raffinose. 

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