D-Gulonic acid

An application to n-xylose (LXII) of the Fischer synthesis of 2-amino hexonic acids from pentoses would lead theoretically to a mixture of 2-amino-D-gulonic acid (LXIII) and 2-amino-D-idonic acid (LXIV). 

N-methyl-l,2-diphenylethylamine, 34, 64 tetraphenylarsonium chloride hydrochloride, 30, 97 Guanidine, 32, 96 Guanidine hydrochloride, 32, 45 Guanylthiourea, 35, 69 D-GuLONIC ACID, y-LACTONE, 36, 38... 

Both L-gulose12,13 (9) and D-gulose (d-9, see Ref. 10) have been oxidized with bromine to L- or D-gulonic acid, respectively (see Scheme 1). L-Gulose (9) has been prepared by a number of different procedures. Schemes 2 and 3 show two early procedures that afforded L-gu-lose, but the overall yields were low (<30%). In the first procedure12 (see Scheme 2), D-glucitol (10) was converted into 2,4-O-benzylidene-D-glucitol (11), which was then oxidized with lead tetraacetate to 2,4-O-benzylidene-L-xylose (12). Nitromethane was added to 12 to afford crystalline 13 in 50% yield. Hydrolysis of 13 provided 14, which was treated with sodium hydroxide, followed by sulfuric acid, to afford 9, which was isolated in 52% yield as the 2-benzyl-2-phenylhydrazone. 

A short synthesis of D-gulono-1,4-lactone (2) from the inexpensive and readily available D-xylose (34) was first reported by Fischer and Stahel,18 and subsequently by others,12,25-31 and is shown in Scheme 6. The addition of hydrogen cyanide to D-xylose (34) resulted in the formation of cyanohydrins 35 and 36 which, on hydrolysis, afforded a mixture of D-gulonic acid (4) and D-idonic acid (37). D-Gulono-1,4-lactone may be obtained in 30-33% yield by recrystallization of the reaction products. In a similar way, L-xylose (l-34) has been converted32,33 in high yield into a mixture of L-gulonic and L-idonic acids. 

Finally, oxidation experiments on D-gluconic and D-gulonic acid produced the head-to-tail enantiomers D/L-glucaric acid. Thus, it was apparent that these acids could only be derived from D-glucose and D-gulose. In a seminal report published in 1891, Fischer... 

D-Ascorbic acid was prepared by Gatzi and Reichstein28 by oxidation of diacetone-D-sorbose to 2-keto-D-gulonic acid, and a desoxy derivative, 6-desoxy-L-a8corbic acid, with some vitamin activity, was synthesized from L-sorbomethylose.116... 

D-Gulonic acid, 2-amino-2-desoxy-, II, 62 —, 5-keto-, III, 147 —, 1,4-lactone, oxidation of, III, 147 —, 1,4-lactone, reduction of, IV, 216 D-Gulo-L-toZo-heptitoI, I, 11, 17 L-Gulonic acid, oxidation of, II, 85 L-Gulonic add, 6-desoxy-2-keto-, II, 87 —, 2,3 4,6-diisopropylidene-2-keto-, III, 164... 

One very interesting case is that of L-rhamnose. Hart and Everett obtained not only the expected 5-keto-L-rhamnonic acid but also 5-keto-L-mannonic acid (5-keto-D-gulonic acid) this was the first reported instance in which a — CH3 group had been oxidized by bromine water to a — CHaOH group. The yields of the brucine salts of the two acids were... 

Glycosylmanganese pentacarbonyl complexes have been characterized on the basis of H-, and Mn-NMR spectral data, and ten tungstate and seven molybdate complexes of D-gulonic acid in aqueous solutions have been identified by multinuclear NMR studies ( H, O, Mo,... 

The 7-lactone of D-gulonic acid was prepared by way of a cyanohydrin derived from an aldopentose. 

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