Mannosamine 6-phosphate, glucosamine

Of significance are D-glucosamine and D-mannosamine (Fig. 29). d-G1ucos-amine-6-phosphate is formed from fructose-6-phosphate by the pathway given in Fig. 32. It is subsequently transformed to iV-acetylglucosamine-6-phosphate and iV-acetylmuramic acid. Synthesis of D-glucosamine-6-phosphate includes an intramolecular oxidoreduction at positions 1 and 2 transforming the ketose to an aldose derivative. 

Heyns and Koch succeeded [96] in confirming the structure of the rearrangement product from the reaction of D-fructose and ammonium chloride in the presence of phosphate and proposed a mechanism (Scheme 28). They pointed out that both epimers at position C-2, D-glucosamine (4) and D-mannosamine (5), were formed with the thermodynamically more stable compound 4 preponderating and recognized that this reaction is related to the Lobry de Bruyn -... 

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