Sorbose chloride

Diacetone-L-sorbose (DAS) is oxidized at elevated temperatures in dilute sodium hydroxide in the presence of a catalyst (nickel chloride for bleach or palladium on carbon for air) or by electrolytic methods. After completion of the reaction, the mixture is worked up by acidification to 2,3 4,6-bis-0-isoptopyhdene-2-oxo-L-gulonic acid (2,3 4,6-diacetone-2-keto-L-gulonic acid) (DAG), which is isolated through filtration, washing, and drying. With sodium hypochlorite/nickel chloride, the reported DAG yields ate >90% (65). The oxidation with air has been reported, and a practical process was developed with palladium—carbon or platinum—carbon as catalyst (66,67). The electrolytic oxidation with nickel salts as the catalyst has also... 

Bacterial oxidation of ribitol (adonitol XXX) affords L-adonose or L-erythropentulose (XXXI) (c/. the bacterial oxidation of sorbitol to L-sorbose). By the agency of methyl alcoholic hydrogen chloride, XXXI yields methyl L-adonoside (XXXII) and condensation of the... 

The variation in the antiscorbutic activity displayed by the various analogs of L-ascorbic acid makes it abundantly clear that the activity is dependent upon the stereochemical configuration of the molecule as a whole, and it would appear that the more closely the structure of a particular analog approaches that of the natural Vitamin C the greater will be the antiscorbutic power. Support for this view is illustrated by 6-desoxy-L-ascorbic acid which is obtained from L-sorbose.2 -80 Condensation of L-sorbose with acetone gives a mixture of 2,3-isopropylidene-L-sorbose (LII) and the diisopropylidene derivative. Treatment of LII with p-toluenesulfonyl chloride yields l,6-ditosyl-2,3-isopropylidene-L-sorbose (LIII). The greater reactivity of the tosyl group at C6 enables... 

Mono(2-aminoethyl) isocyanurate, 3 202 2,3-Monoacetone-L-sorbose (MAS) in ascorbic acid manufacture, 25 757 Monoacid chlorides, of maleic anhydride, 15 484-486... 

Dialkyl dithioacetal derivatives of ketoses, such as D-fiuctose and L-sorbose, me inaccessible directly from the parent sugars, the ketose undergoing extensive decomposition under the conditions employed for mercaptaladon of aldoses. Such derivatives can, however, be prepared by indirect methods. Acetylation of D-fiuctose [40] and L-soibose with acetic adiydride and zinc chloride [41] leads to good yields of acyclic pentaacetates in which foe ketose carbonyl is not involved in a cyclic acetal. Subsequent treatment of these acetylated derivatives with thiols affords foe acetylated dialkyl dithioacetals in satisfactory yields, and conventional deacetylation affords foe unprotected dialkyl dithioacetals [40,41]... 

L-Sorbose (3.60 g, 20.0 usd) is added to a Stirling aolntion of anhydrous zinc chloride (0.36 g) and acetic anhydride (70 mL) at 0°C. After allowing the reaction to warn to room temperature, the mixture is stirred for 3 h, allowed to stand for a further 30 h, and then pouwdinto water (300mL) with stirring. The mixture is stirred for 3 h to decompose excess acetic anhydride, and then the sriiid mass is filtered andwcfystaWiwid from ethanol to yield die pentaacetate (5.4 g, 70%) mp 96S-91-5°C, [tel, +2.V (c 2.14, chloroform). 

An alternative procedure for the protection of L-sorbose (25), followed by oxidation at C-l and cyclization of the product to L-ascorbic acid, was developed by Hinkley and Hoinowski.257 L-Sorbose (25) was converted into methyl a-L-sorbopyranoside (37) by treatment with methanol and hydrogen chloride.258 Glycoside 37 was then oxidized with air in the presence of a suspension of platinum oxide in aqueous sodium hydrogencarbonate solution at 60°, to afford methyl ot-L-xylo-2-hexulopyranosidonic acid (38), which, when heated in hydrochloric acid, was converted into L-ascorbic acid (1), presumably by way of L-xy/o-2-hexulosonic acid (see Scheme 5). Acid 38 has also been prepared by oxidation of 37 with nitrogen tetraoxide.259,280 Yields were not reported for this reaction sequence, and it appears to offer no potential... 

In a series of reactions similar to those used in the preparation of D-psicose, Wolfrom, Olin and Evans30 synthesized D-sorbose (II) from D-xylonyl chloride tetraacetate (XIX) via the l-desoxy-l-diazo-fcefo-D-sorbose tetraacetate (XX) and fcefo-D-sorbose pentaacetate (XXI). 

A synthesis of L-sorbose by the diazomethane reaction on 2,4 3,5-diethylidene-L-xylonyl chloride (XXX) was performed by Gatzi and Reichstein.54 Oxidation of 3,5 4,6-diethylidene-L-gulitol (l,3 2,4-dieth-ylidene-D-glucitol) (XXVIII) gave the diethylidene-L-xylonic acid (XXIX). Addition of diazomethane to the acid chloride (XXX) yielded a sirupy diazoketone (XXXI) from which L-sorbose (XXXII) was obtained by acid hydrolysis with dilute sulfuric acid. 

A sirupy pentapropionate of L-sorbose was described by Hurd and Gordon.142 Crystalline esters of L-sorbose, such as the 1-benzoyl-,55 1-p-aminobenzoyl-148 and 1-tosyl-, 144,56 have also been synthesized. 1-p-Aminobenzoyl-L-sorbose was prepared as a possible substance for measuring the rate of glomerular filtration. It was synthesized by esterifying 2,3 4,6-diisopropylidene-L-sorbose with p-nitrobenzoyl chloride, with subsequent reduction of the nitrobenzoyl ester to 1-p-amino-benzoyl-2,3 4,6-diisopropylidene-L-sorbose. Removal of the isopropyli-dene groups by dilute acid hydrolysis furnished the desired product. 1-Tosyl-L-sorbose was independently prepared by two different methods. The first method,55 discussed on page 110, involves the oxidation of a properly substituted sorbitol derivative, while the latter method144 is similar to the one used for the preparation of the 1-p-aminobenzoyl derivative, namely esterification of 2,3 4,6-diisopropylidene-L-sorbose, followed by acid hydrolysis. This cyclic acetal has also been esterified to the crystalline l-mesyl-2,3 4,6-diisopropylidene-L-sorbofuranose by... 

The rates of reaction of diisopropylidene derivatives of L-sorbose, D-glucose and D-galactose with an excess of triphenylmethyl chloride in pyridine, have been studied.162 Similar studies were then conducted on the reactivity of these diisopropylidene derivatives with p-toluene-sulfonyl chloride.168... 

Kuhn and Strobele were able to cause such weakly basic amines as o-nitroaniline to react with sugars by adding a 0.05 molar proportion of ammonium chloride and, in a similar manner, Frerejacque used methanol containing 4 % of aqueous acetic acid. Hydrogen chloride was employed by Kuhn and Birkofer to induce reaction between p-phenetidine and D-fruc-tose, L-sorbose, and D-mannose. 

A yield of 60 to 70% of 3,5 4,6-di-0-ethylidene-L-gulonic acid can be readily obtained by the oxidation of one mole of 1,3 2,4-di-0-ethylidene-D-glucitol in the presence of one mole of alkali.According to a patent by D Addieco, this acid can be oxidized to 3,5 4,6-di-O-ethylidene-D-a 2/io-hexulosonic acid by sodium hypochlorite in the presence of nickelous chloride. After hydrolysis of the acetal groups, this acid can be rearranged to L-ascorbic acid. Thus, this provides, for vitamin C, a synthesis which does not require L-sorbose and does not involve bacterial oxidation. A 33% yield of D-xj/fo-hexulosonic acid is obtained. However, nothing is men-... 

The 1,2-0-isopropylidene derivative 100, derived from L-sorbose, was also used for the synthesis of 1-deoxynojirimycin (2) (Scheme 19) It was prepared from L-sorbose by reaction with 2,2-dimethoxypropane in the presence of stannous chloride, followed by acid hydrolysis. Selective sulfonylation of the primary hydroxyl group with 2,4,6-triisopropylbenzenesulfonyl chloride (TIBSCl) in a 1 1 mixture of triethylamine and pyridine followed by nncleophilic displacement with azide ion in DMF afforded the 6-azido-... 

These reactions may be accompanied by unwanted side-reactions, such as oxidation of hypobromite to bromate or its reduction to bromide. The electro-oxidation of 2,3 4,6-di-0-isopropylidene- -L-sorbofuranose (14) is affected by a number of factors, and here the method of mathematical planning of so-called extreme experiments for obtaining the optimal conditions for electrolysis was utilized the conditions are concentration of sodium bromide, 107.7 g per liter concentration of nickel chloride, 0.71 g per liter concentration of 2,3 4,6-di-0-isopropylidene-L-sorbose, 86 g per liter the amount of electric current passed, 1.912 A-hr/g of the diisopropylidene acetal current density, 4.56 A.dm pH of the solution, 9.83 the expected yield, 91.9 0.7%. A more-detailed survey of the mechanism and kinetics of the electrochemical oxidation of monosaccharides and their derivatives, as well as of the effect of experimental conditions on the yields of aldonic acids and of the di-O-isopropylidene-xylo-hexulosonic acid (15) formed, has been given. ... 

A number of new acetonation conditions have been examined. Use of acetone in the presence of K 10 clay gave the 2,3-0-isopropylidene derivatives of d-ribofuranose and L-rhamnopyranose and the expected di-O-isopropylidene derivatives of D-xylose, D-glucose, D-galactose and D-mannose in excellent yields. Good to excellent yields of the expected acetonides of methyl a-D-manno-, a-D-gluco-, and a-D-galacto-pyranoside as well as of D-mannose have been obtained with acetone and titanium(IV) chloride supported on modified silica gel. H3PM012O40 was the most active of 18 heteropolyacids examined as catalysts in the acetonation of L-sorbose. ... 

Photochemical reactions of monosaccharides with Iron(III) chloride have been reported In Chapter 2. L-Sorbose and trls-(ethylenedlamlne)nlckel(II) chloride give a crystalline cationic... 

The acyclic alkene (27) was produced amongst the compounds formed by benzoylation of L-sorbose at room temperature with benzoyl chloride in pyridine on ozonolysis it gave 2,3,4,5-tetra-O-benzoyl-L-xylonic acid. The diene (28) is a product of base-catalysed acetylation of Dmannuronolactone. ... 

As noted above, the ketoses are especially prone to produce acyclic acetates by methods of direct acetylation, as exemplified by D-fructose 1) and D-sorbose 23). It has been demonstrated by Pacsu 1) and by Wolfrom and Thompson 1) that the long known penta-0-acetyl- a -D-fructose of Hudson and Brauns 1) has a free ketonic group. A general method, involving the action of diazomethane on 0-acetylated aldonic acid chlorides, has been developed for the synthesis of 0-acetyl-fceZo-sugars 24) (see formulas). 

The rates of reaction of triphenylmethyl chloride with several characteristic compounds are given ( 7) in Table I, which also illustrates the effect of the trityl chloride concentration. For the 8-fold excess, the primary alcoholic group of the galactose derivative reacts 226 times as rapidly as the secondary alcoholic group of the glucose derivative. However, the difference between the primary alcoholic group of the sorbose derivative and the secondary hydroxyl of the glucose derivative is only 34 times. 

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