Sorbitol, structure

SN1 reaction and, 379-380 Sjvj2 reaction and, 370-371 Sorbitol, structure of, 992 Spandex, synthesis of, 1214 Specific rotation, 295 table of, 296... 

The Raman spectra obtained for the sorbitol samples are shown in Figure 8, with identical spectra being obtained for each. The Raman spectral assignments are presented in Table 10, and the measured Raman bands are consistent with the sorbitol structure. 

Therapeutic Function Cholecystokinetic, Diuretic, Pharmaceutic aid Chemical Name D-Glucitol Common Name d-Glucitol Sorbit Sorbitol Structural Formula ... 

It is important to note that if the distillation of water from sorbitol solutions is conducted at too high a temperature, for example in excess of 140 °C, cyclic ethers called sorbitans are formed (by the intramolecular etherification of sorbitol), which have lower functionality than sorbitol (structures 13.19 and 13.20). 

Sorbitol is a sweetener often substituted for cane sugar because it is better tolerated by dia betics It IS also an intermediate in the commercial synthesis of vitamin C Sorbitol is prepared by high pressure hydrogenation of glucose over a nickel catalyst What is the structure (including stereochemistry) of sorbitoP... 

Fig. 2. Structures of hexitols (a) allitol, (b) sorbitol (D-glucitol), (c) D-maimitol, (d) dulcitol, (e) L-iditol, and (f) D-altritol.

The structure of these products is uncertain and probably depends on pH and concentrations in solution. The hydroxyl or carboxyl or both are bonded to the titanium. It is likely that most, if not all, of these products are oligomeric in nature, containing Ti—O—Ti titanoxane bonds (81). Thek aqueous solutions are stable at acidic or neutral pH. However, at pH ranges above 9.0, the solutions readily hydroly2e to form insoluble hydrated oxides of titanium. The alkaline stabiUty of these complexes can be improved by the addition of a polyol such as glycerol or sorbitol (83). These solutions are useful in the textile, leather (qv), and cosmetics (qv) industries (see Textiles). 

Hydrogenation reactions, particularly for the manufacture of fine chemicals, prevail in the research of three-phase processes. Examples are hydrogenation of citral (selectivity > 80% [86-88]) and 2-butyne-l,4-diol (conversion > 80% and selectivity > 97% [89]). Eor Pt/ACE the yield to n-sorbitol in hydrogenation of D-glucose exceeded 99.5% [90]. Water denitrification via hydrogenation of nitrites and nitrates was extensively studied using fiber-based catalysts [91-95]. An attempt to use fiber-structured catalysts for wet air oxidation of organics (4-nitrophenol as a model compound) in water was successful. TOC removal up to 90% was achieved [96]. 

FIGURE 1.1 Structures of organic compounds referred to in the text (a) sucrose (also known as saccharose), (b) dimethyl sulfoxide (DMSO), (c) dimethylformamide (DMF), (d) sorbitol, (e) mannitol, (f) nitrilotriacetic acid (NTA), (g) citric acid, (h) N,N,N, N -fran,s-1,2-diaminocyclohexane-tetraacetic acid (CyTA), (i) saccharic acid, (j) glutamic acid. 

As described above, understanding the mechanism of the dispersion increase is a difficult task. In this work we compare a catalyst prepared by cobalt nitrate impregnation onto alumina with one modified by the addition of mannitol, and use TGA and in situ microscopy to investigate the increased dispersion. Mannitol is a sugar alcohol that is structurally similar to sorbitol [31], as shown in Figure 1.1. 

A simple relationship was not found between shrinkage and glass - rubber transitions of both peach and apricot tissue (Campolongo, 2002 Riva et al., 2001, 2002). Even when sorbitol use increased AT (= T — 7g ) values, both the color and the structure showed the highest stability. The fact that sorbitol performed better than sucrose indicates that the chemical nature of the infused solute is more important than its glass transition temperature in preventing structural collapse, in accordance with the results reported by del Valle et al. (1998). 

The 3,6-anhydro-D-glucose (XIX) of Fischer and Zach13 on reduction with sodium amalgam or with hydrogen in the presence of Raney nickel14 gives 3,6-anhydro-D-sorbitol (XX), a method of synthesis which establishes the ring structure of the substance since that of 3,6-anhydro-D-... 

Dianhydro-n-mannitol or isomannide was first prepared many years ago by Fauconnier44 who obtained it by heating D-mannitol with hydrochloric acid. The dianhydrides of D-sorbitol and L-iditol were not prepared, however, until very recent times. Although isomannide is a crystalline substance forming well defined derivatives very little work has been carried out on it and its structure was not determined until 1945, but in that and the following years a flood of experiments having a... 

Since no other stereoisomer but that of iditol, mannitol or sorbitol can exist in the as-fused ring series of l,4 3,6-dianhydrohexitols and since amination experiments on the ditosyl derivatives of each isomer have given three different amino derivatives, it is reasonable to assume that the two diamines which have been isolated are of the same configuration as their parent dianhydrohexitols. These two diamines LXXIV and LXXV on treatment with nitrous acid suffered deamination as expected but instead of obtaining in one case isomannide and in the other isosorbide, only one dianhydrohexitol was isolated and that was dian-hydro-L-iditol. The deamination must of course lead to the transitory carbonium cation LXXVIII and this on hydroxylation can take on any of the configurations, L-iditol, D-mannitol or D-sorbitol. That it preferentially takes on the configuration of L-iditol indicates that this is in some ways a more stable structure than the others. This behavior is paralleled... 

The selective functionalization of saccharose and sorbitol with fatty acids for the construction of a perfect amphiphilic structure cannot be realized in simple technical processes because of the polyfunctionality of the molecule. This is why the products offered on the market contain different amounts of mono-, di- and... 

Recent 620.6 MHz nmr results on sorbitol and mannitol (9) confirm that sorbitol rotates more freely in water than mannitol. This suggests that there is less solute-solvent interaction in sorbitol. Calorimetric results (J ) predict that sorbitol and mannitol should have hydration behavior similar to that described above. Those workers, however, referred to structure breaking properties, even though no structural data was obtained. 

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