Über aldose-2,-4 dinitro- und 4-nitro-phenyl- hydrazone

Abstract

The writer and his collaborators have the structure of 2,4-dinitro- and 4-nitro-phenyl hydrazones of d-glucose, d-xylose, d-mannose, d-arabinose, and d-galactose investigated. With the purpose of determination of the structure the hydrazones have been—following Hofmann's method— at about 0° acetylated and on this way two types of O-acetyl hydrazones have been produced. The 2,4-dinitro-phenyl hydrazones of d-glucose, d-xylose, d-mannose and the 4-nitro-phenyl hydrazone of d-glucose resulted O-acetyl hydrazones of ring-structure. These hydrazones could be transformed in open-chain ones by acetylation at about 100°. The structure of the latter compounds has been proved by synthesis. The U.V. absorption of the two types of hydrazones differs at about 260 mμ. The relative stability of the pyranose ring of O-acetyl- d-glycose-, - d-xylose- and - d-mannose-2,4- dinitro-phenyl hydrazone has been also quantitatively determined. As a result of the investigations on the reactions of aldose hydrazones it has been stated that into derivatives of tetrahydro-furfural hydrazone could be transformed the following compounds: 2-oxy-3-chloro-tetrahydropyran, 2,5- dioxyvaleraldehyd-4′-nitro-phenyl hydrazone and 2-desoxy-2-bromo-3,4-diacetyl d-xylose.