6-amino-L-sorbose

Figure 16.2-41. Oxidation of N-protected 1-amino-D-sorbi-tol to 6-amino-L-sorbose using Gluconobacter oxydans.

In 1923 the bacterium Acinetobacter suboxydans was isolated and, starting in 1930, was used for the industrial oxidation of L-sorbitol to L-sorbose in the Reichstein-Griissner synthesis of vitamin C[39]. Bayer uses the same type of reaction, but instead of Acinetobacter the bacterium Gluconobacter suboxydans is used in the oxidation of N-protected 6-amino-L-sorbitol to the corresponding 6-amino-L-sorbose, which is an intermediate in miglitol production (Fig. 19-7). 1-Desoxynojirimydn is produced by chemical intramolecular reductive amination of 6-amino-L-sorbose. In contrast, the... 

The protonated amino group, however, has no nucleophilic activity, and does not form a hemiacetal an amino sugar can, therefore, be obtained, as a salt, in an otherwise unfavorable form. For example, 6-amino-6-deoxy-L-sorbose can be isolated as the hydrochloride of a furanose form (22) (presumably a). In alkaline solution, immediate ring-expansion to the pyranose form (23) occurs127 this reaction can be reversed under strongly acidic conditions. 4-Amino-4,6-dideoxy-D-glucose hydrochloride forms a 35 65 mixture of the a- and / -pyranose forms in solution.128... 

Amino-6-desoxy-L-sorbose hydrochloride Dimethylaminoborane l,5-Didesoxy-l,5-imino-D-glucitol of 6-... 

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... 

G. Kinast, M. Schedel, Verfahren zur Her-stellung von 6-Amino-6-desoxy-L-sorbose,... 

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