Glucitol study

Irradiation of unprotected carbohydrates was the subject of greatest photochemical interest to the early carbohydrate photochemists.1 The investigations of these early workers were concerned primarily with the effect of reaction conditions upon the photochemical process, rather than with the identity of the reaction products. Between 1960 and 1969, a comprehensive series of papers was published on the photochemical reactions of D-glucose and D-glucitol.95-99 These studies contributed greatly to understanding of the photochemistry of unprotected carbohydrates, as not only was the result of variation in the reaction conditions studied but also the structures of the products were determined. 

Photolysis of three 2,4-dinitroanilino-substituted carbohydrates, compounds that differ considerably from each other in photochemical reactivity, has been reported.150,151 l-Deoxy-l-(2,4-dinitroanilino)-D-glucitol (73) is photochemically unreactive in contrast, sodium 2-deoxy-2-(2,4-dinitroanilino)-D-gluconate (74) produces D-arabinose in 52% yield upon irradiation.150 The behavior of compounds 73 and 74 indicates that oxidative loss of the 2,4-dinitroanilino group during photolysis is only possible when it is accompanied by simultaneous decarboxylation. The evidence gathered from the considerable study of this reaction for noncarbohydrate systems suggested that this process is quite complex. Although useful, mechanistic proposals have... 

In connection with the structure of glycoproteins, Lloyd and Kabat studied the separation of six alditol acetates,452 and Kim and coworkers57 examined the separation of L-fucitol, D-glucitol, D-manni-tol, and galactitol. Alditol acetates have been used in studies on... 

The quantitative determination of uronic acids in polysaccharides is complicated by lactonization, and these problems have been carefully examined by Blake and Richards.26,98 In the course of these studies, D-glucuronic acid was reduced to D-glucitol, which was characterized as the hexaacetate.98 As uronic acid residues in a polysaccharide may be reduced relatively easily,465,466 determination as the alditol provides an alternative method of analysis.461,468 This procedure is most valuable when different uronic acids are present in... 

Jackson and Hayward59hydroxyl group in l,4 3,6-dianhydro-D-glucitol is preferentially sulfonylated prior to conversion into the mixed ester is incorrect. They based their conclusions on studies of the rate of replacement of p-tolylsulfonyloxy group by iodide in the three dianhydro stereoisomers. However, their proof of structure was questioned by Lemieux and Mclnnes59acetoxonium intermediate prior to attack by the iodide ion. 

Makkee, M., A.P.G. Kieboom, and H. van Bekkum, Studies on borate esters IU. borate esters of D-mannitol, D-glucitol, D-fructose and D-glucose in water. Reel. Trav. Chim. Pays-Bas, 1985. 104(9) p. 230-235. 

This last reaction (RM) enables us to understand the formation of products containing 3 carbon atoms (glycerol, 1,2-propanediol) from glucitol (sorbitol) but is always in competition with the two other ones (DOH, RC). The ratio of these three reactions, determining the conversion selectivity, depend widely on the copper origin (Raney, deposited on a support, impurities, activation process). So, we studied the influence of additives deposited on Raney copper on these reaction selectivities. 

Protonation occurs preferentially at the primary hydroxyl group. The first dehydration step can also take place between the 3- and 6-position, leading to the 3,6-monoanhydro derivative 41. The second water-elimination step from the 1,4-, as well as from the 3,6-, anhydro-D-glucitol, leads to the formation of D-isosorbide. However, kinetic studies showed94 that the proportion of the 3,6-anhydro isomer is low compared to that of the 1,4-anhydride. An investigation giving similar results is described in Ref. 95. 

Further studies verified the intermediate formation of free radicals, as demonstrated by the electron-spin resonance spectra obtained during autooxidation of cellulose,75 and hydrogen peroxide was identified as a byproduct in the autooxidation of D-glucitol. Similar oxidations of cellulose in the presence of alkenic monomers afforded graft copolymers. The autooxidation of cellulose and of the cello-oligosaccharides was shown to be more extensive in the presence of transition-metal cations. 

GLUCIT01, D-Glucitol (form A, neutron study) (CgH Og). Park YJ, Jeffrey GA, Hamilton WC (1971) Acta Crystallogr, Sect B 27 2393... 

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