Psicose phenylosazone

L-Allose phenylosazone, prepared from L-psicose, was decomposed by benzaldehyde to L-allosone, which was converted into L-alloascorbic acid.187... 

The powdered-cellulose, flowing chromatogram of an unfermentable residue from the mixture obtained by the action of heat on n-fructose yielded a sirup containing a ketose having a mobility greater than that of D-fructose it may be n-psicose. D-Psicose (identified as the phenylosazone... 

Occurrence. D-Psicose (D-rifeo-hexulose, 30) is produced in the hydrolysis of the antibiotic psicofuranine.147,148 Although the sugar was initially isolated only as the phenylosazone, its identity was proved by synthesis of psicofuranine from tetra-0-acetyl-D-psicosyl chloride. The ketose also occurs in Itea plants, from which it has been isolated as the diisopropylidene acetal.149... 

In addition to fructose (Practice Problem 22.12) and sorbose (Problem 22.24), there are two other 2-ketohexoses,/> V< reand tagatose. D-Psicose yields the same phenylosazone as D-allose (or D-altrose) D-tagatose yields the same osazone as D-galactose (or D-talose). What are the structures of D-psicose and D-tagatose ... 

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