Glucitol ester

A series of sorbitol-based nonionic surfactants are used ia foods as water-ia-oil emulsifiers and defoamers. They are produced by reaction of fatty acids with sorbitol. During reaction, cycHc dehydration as well as esterification (primary hydroxyl group) occurs so that the hydrophilic portion is not only sorbitol but also its mono- and dianhydride. The product known as sorbitan monostearate [1338-41 -6] for example, is a mixture of partial stearic and palmitic acid esters (sorbitan monopalmitate [26266-57-9]) of sorbitol, 1,5-anhydro-D-glucitol [154-58-8] 1,4-sorbitan [27299-12-3] and isosorbide [652-67-5]. Sorbitan esters, such as the foregoing and also sorbitan monolaurate [1338-39-2] and sorbitan monooleate [1338-43-8], can be further modified by reaction with ethylene oxide to produce ethoxylated sorbitan esters, also nonionic detergents FDA approved for food use. 

The influence of other radicals in the stabilization of dihydroxytetrahy-drofuran rings should also be considered, as, for example, the p-toluene-sulfonic esters.41 When the compound LXI is hydrolyzed by acids, it gives the 2,5-anhydro derivative (LXII), whereas the compound LXIII gives D-glucitol. 

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. 

Circular dichroism of the nitrato (ONO) chromophore of the mono- and di-nitric esters of l,4 3,6-dianhydrohexitols was found to consist of two dichroic bands, one weak and positive, at about 265 nm, and a stronger band at —228 nm, which was positive for the endo-(R)-nitrato chromophore and negative for the exo-(S)-nitrato group.68 However, for l,4 3,6-dianhydro-D-glucitol dinitrate, which has both an endo and an exo nitrato group, both bands were positive, but [ ]ma r (+ 7,260) for the band at 225 nm was about half of the algebraic sum of this band for the di-endo (+ 18,400) and di-exo (—4,460) compounds. 

The presence of alkoxide ion would enhance the rate of ammonolysis, and the formation of bis(amido) derivatives by an ortho-ester mechanism (see Section VI, p. 110) would be partially suppressed in the competitive set of reactions. Thus, ammonolysis of penta-O-benzoyl-D-glucose in the presence of 5 mmolar proportions of sodium meth-oxide showed a decrease of 11% in the yield of the bis(benzamido)-glucitol derivative as compared with the same reaction conducted without added methoxide ion.47... 

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. 

In the course of the synthesis173 of oxaprostaglandins from 1,4 3,6-dian-hydro-D-glucitol, the latter was first monotosylated at the 5-position and the ester benzylated, to afford 82. Elimination of the tosyl oxy group under special conditions yields the enolethers 83 and 84 (see Scheme 16) as a 2 1 mixture which can be separated by column chromatography. 

The only recorded examples of carbohydrate trithiocarbonates were prepared by McSweeney and Wiggins in 1951. These authors caused 5,6-an-hydro-1,2-0-isopropylidene-n-glucofuranose to react with carbon disulhde and potassimn hydroxide in boiling methanol, and allegedly obtained 1,2-0-isopropylidene-5,6-dithio-n-glucofuranose 5,6-trithiocarbonate (see p. 102). The related derivatives from 5,6-anhydro-l, 3 2,4-di-0-ethyUdene-D-glucitol and 5,6-anhydro-l, 2 3,4-di-O-isopropylidene-D-mannitol were also synthesized, in a similar manner. All three esters could be desulfurized with Raney nickel to the corresponding dideoxy compounds. 

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