D-Glycerose

D-Glycerose CH2OH CH2OH CHjOH CHjOH CH2OH CH2OH CH2OH CH2OH... 

The reaction of D-glycerose with ethyl acetoacetate occurs in dilute, aqueous solution in the presence of zinc chloride,15 giving compound IX when saponified, this affords the crystalline acid X. Proof of the structure... 

Glycolaldehyde also reacts in dilute solution with ethyl acetoacetate, under conditions analogous to those for D-glycerose, to give ethyl 2-methyl-3-furoate.16 The corresponding acid was identified as 2-methyl-3-furoic acid (IV). 

These observations, as yet incomplete, are now being extended by studies with D-glycerose and its phosphoric esters, particularly because of the biological importance of these compounds.16... 

A mixture of 2.65 g. of freshly distilled 2,3-O-isopropylidene-D-glycerose, 1.5 ml. of ethyl acetoacetate, 0.7 g. of zinc chloride, 20 ml. of N sulfuric acid, and 20 ml. of 96% ethyl alcohol is kept at room temperature for twenty-four hours. After addition of 3 g. of crystalline sodium acetate and keeping for a further 48 hours at room temperature, the mixture is heated for 15 minutes at 90°. It is then repeatedly extracted with ether, and the united extracts are successively washed with water, an aqueous solution of sodium bisulfite, and a small quantity of aqueous sodium hydroxide solution. The ether layer is dried with anhydrous sodium sulfate and the solvent is evaporated, yielding an oil which is saponified with aqueous sodium hydroxide solution (4 ml. of 10%) by heating on a steam bath for one hour. The aqueous solution is extracted with ether, acidified (to Congo Red) with phosphoric acid, and then repeatedly extracted with ether the united extracts are dried with anhydrous sodium sulfate and the solvent is evaporated, giving a residue which crystallizes from water yield, 0.2 g. of the product (X) m. p., 153-155°. 

Hexose diphosphate was found by Harden and Young69 in cell-free alcoholic-fermentation liquors. In 1930, it was observed that addition of fluoride to fermenting-yeast extracts leads to an accumulation of 0-phospho-D-glyceronic acid,60 which is also a metabolite of muscle extracts.61 Attention was turned, therefore, to the pathway from hexose diphosphate to 0-phos-pho-D-glyceronic acid. In 1932, Fischer and Baer62 described the synthesis of D-glycerose 3-phosphate, and, in 1933, Smythe and Gerischer63 noted... 

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... 

Jack-bean aldolase and liver aldolase catalyze the conversion of one mole of D-fructose 1-phosphate into one mole each of dihydroxyacetone phosphate and D-glycerose, and the reaction is reversible.73-77... 

A triokinase, isolated from liver, phosphorylates both D-glycerose and DL-glycerose, at the same rate, in the presence of adenosine-5-triphosphoric acid (ATP), and phosphorylates dihydroxyacetone at approximately half the rate.77-78... 

It has been suggested that one molecule of the branched-chain hexose hamamelose [2-(hydroxymethyl) -D-ribose] (XXX) could arise from an aldol-type of interaction of two molecules of D-glycerose.16 This suggestion is sup-... 

D-alJro-Heptulose 7-phosphate + D-glycerose 3-phosphate D-fructose 6-phosphate + D-erythrose 4-phosphate... 

D-erythro-Pentulose 5-phosphate (XLIV) has been formed by the action of transketolase on hydroxypyruvate (XLII) and D-glycerose 3-phosphate, the hydroxypyruvate being decarboxylated196 to active glycolaldehyde which then reacts with the triose phosphate by an acyloin reaction.28 The active glycolaldehyde is also formed from L-glycero-tetrulose, d-altro-heptulose 7-phosphate, D-fructose 6-phosphate, and D-i/ireo-pentulose 5-phosphate and it reacts with various aldehydes (acceptors) to give ketoses.198, 200 Thus, substitution of L-gfh/cero-tetrulose for hydroxypyruvate in the above experiment also resulted in formation of D-en/i/iro-pentulose... 

Acetaldehyde combines with 2,3-O-isopropylidene-D-glycerose, in the presence of potassium carbonate, to give 2-deoxy-4,5-O-isopropylidene-D-ribose and -D-xylose,46 suggesting a possible biosynthetic route (see Reference 46). The suggestion that 2-deoxy-D- ribose (2-deoxy-D-erythro-pentose) arises by combination of acetaldehyde with D-glycerose 3-phosphate to give 2-deoxy-D-ribose 5-phosphate (LX) was verified by using enzyme... 

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