DL-Sorbose

Schmitz found that the aldolization of DL-glycerose in barium hydroxide solution, which is accompanied by isomerization of the DL-glycerose to 1,3-dihydroxy-2-propanone, gave DL-fructose and DL-sorbose. Similarly, Fischer and Baer ... 

Readily obt. from DL-sorbose/anhyd. HE Almost insol. cold H2O spar. sol. hot H2O. Mp 320°. 

Dihydroxyacetone phosphate reacts with D-glycerose in the presence of aldolases of muscle and liver to give D-fructose 1-phosphate (XII) exclusively, whilst DL-glycerose forms equimolar proportions of D-fructose 1-phosphate (XII) and L-sorbose 1-phosphate (XIII).65 Specificity of the enzyme is interesting in the light of Fischer and Baer s observations66 in... 

Scheme 7.—The Equimolar Mixture of D-Fructose and L-Sorbose Obtained from dl-2,3-Dihydroxypropanal in the Reaction Catalyzed by the Glycolysis Aldolase.

Iron(III)hydroxide oxide [Fe(0H)0] has been shown to catalyze the condensation of 25-mM DL-glyceraldehyde to ketohexoses at 15 °C (pH 5-6). After 16 days 15.2% of sorbose, 12.9% of fructose, 6.1% of psicose, 5.6% of tagatose, and 2.5% of dendroketose are obtained. After 96 days at 15 °C this mixture was not decomposed. [Fe(0H)0] also catalyzes the isomerization of glyceraldehyde into dihydroxy acetone and of dihydroxy acetone into lactic acid [41]. 

Optimum conditions for the oxidation of the primary hydroxy group of 2,3 4j6-dl-2-isopropylldene-L-sorbose at a chromium-nickel steel grid anode were developed to give yields In excess of 70%. ... 

On the other hand, the product from glucose is an exceedingly complex mixture, the composition of which varies with the conditions of treatment. D-Psicose (from treatment with ammonia) (55) and (dl + n)-sorbose (from treatment with a strong base resin) 90) have been identified definitely in the mixture. D-Glucose is readily converted to D-fructose. From the latter has been isolated after treatment with potassium hydroxide (dl + D)-sor-... 

Further reports on the oxidation of 2,3 , 6-dl- -isopropylidene-L-sorbose to the ulosonlc acid acetal have dealt with the kinetics of the reaction carried out with palladium on charcoal in alkaline... 

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