Dehydration gluconate

Moreover, the compound (LV) obtained from the reaction of 2-keto-D-gluconic acid with o-phenylenediamine28 has been dehydrated to give a compound which Maurer erroneously described as LYI. In this case, also, the process of dehydration has been shown to be equivalent to that just described for compound L. The product obtained by interaction of 2-furyl-... 

We have been able to develop a one-step procedure (14) for the preparation of LAGA by acid catalyzed dehydration directly from gluconic acid or from its 1,4- or... 

The sorbitol solution produced from hydrogenation is purified in two steps [4]. The first involves passing the solution through an ion-exchange resin bed to remove gluconate and other ions. In the second step, the solution is treated with activated carbon to remove trace organic impurities. The commercial 70% sorbitol solution is obtained by evaporation of the water under vacuum. The solid is prepared by dehydration until a water-free melt is obtained which is cooled and seeded. The crystals are removed continuously from the surface (melt crystallization). The solid is sold as flakes, granules, pellet, and powder forms in a variety of particle size distributions. 

The preferred method of preparing 74 for laboratory use is by the dehydration of D-xt/lo-5-hexulosonic ( 5-keto-D-gluconic ) acid in refluxing, 5% methanolic hydrogen chloride the crystalline, methyl ester of 74 can then be isolated in 17.4% yield.110 Crystalline 74 is readily prepared from the methyl ester by saponification. Pure 74 has m.p. 200-201° and kmaX = 286 nm (e = 18,000) in water. 

Extreme caution should be used in handling anhydrous HF. It can cause severe bums that may not be noticed immediately but will be very painful later HF dehydrates the skin, and F removes Ca2+from tissues and delays healing. Immediate thorough water washing of any exposed skin should be followed by application of calcium gluconate gel or benzalkonium chloride (trade name Zephiran Chloride), and medical attention is essential. 

Recently, several syntheses of pyridazines from monosaccharides have been described. Calcium 2,5-diketo-D-gluconate reacts with monosubstituted hydrazines to give the corresponding pyridazinium derivatives of the zwit-terionic type 95. ° The reaction proceeds by hydrazone formation, dehydration, decarboxylation, and cyclization. In a similar manner, other... 

The innermost zone covers chemicals for which no petrochemical route exists, and therein lies a great opportunity to produce them from carbohydrate feedstocks (in the case that a market for them is present or arises) gluconic [91,92] and glucaric acids [17], furyl glycolic acid [87], furandicarboxylic acid [85], and fermentation-derived malic, citric, succinic, and itaconic acids [17]. Besides these, the sugar alcohols xylitol [78] and sorbitol [81, 93-95], as well as isosorbide [82, 96, 97], HMF [80,98], and furfural [44,99] are also present, along with tetroses and their derivatives obtained by dehydration [100]. For these molecules, it is virtually certain that no petrochemical-based production will ever be developed. Note that levulinic acid [67, 101-103] is at the border of this zone. 

For the preparation and the dose check, it may be necessary to convert the strength to milligrams per millilitre. In case of the oral solution in this prescription magnesium gluconate dehydrate is used. Therefore, the equivalent strength is 45 mg/mL. The above prescription can then be read as ... 

A 3-deoxy-2-ketogluconic acid 6-phosphate was isolated as an intermediate in the enzymic oxidation of gluconic acid 6-phosphate 135a). The formation of this acid by a dehydration mechanism is reminiscent of that of the saccharinic acids. 

As described in the section on gluconate metabolism, the step catalyzed by glucose-6-phosphate dehydr( nase is essentially irreversible in intact E. coli. Thus the ability to use substrates such as gluconate, n-arabinose, ribulose, and ribose which are inserted in suitable adapted strains of E. coli at various levels in the oxidative pathway involves only... 

Amino-2-deoxy-D-gluconic acid and its, 6-0 -benzylidenated ethyl ester gave enamines, e.g.,(69).on reaction with 3-dicarbonyl compounds these could be lactonized and dehydrated to a,B-unsaturated lactones,e.g.,(70).and thence converted into pyranones e.g.,(71).(Scheme 15). °... 

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