Fructose oxime

Reaction of D-fructose with two molecular proportions of trityl chloride in pyridine for two days at room temperature gave a ditrityl-D-fructose (30% yield), which crystallized (m. p. 96-97°) with two molecules of pyridine. Removal of the pyridine left amorphous ditrityl-D-fructose, [a]D +17.5° in chloroform. This gave a crystalline oxime identical with that obtained by tritylating D-fructose oxime. Helferich148 designates this ditrityl derivative as 1,6-ditrityl-D-fructose without further proof. 

Other compounds identified in caramels are di-D-fructose and poly(glycosyl) dianhydrides (DFAs). DFAs were found in caramels prepared from D-fructose, D-glucose, and sucrose. The analysis was done after derivatization as TMS (per-0-trimethylsilyl) derivatives or as TMS-oxime (per-O-trimethylsilyl oxime) by... 

Bredereck and coworkers also studied the 1,6-ditrityl ether, and definite proof of its structure was afforded by an outstanding series of experiments. The amorphous material (m.p. 94r-96°) was treated with the ordinary acetylation mixture, and yielded 3,4,5-tri-O-acetyl-l,6-di-O-trityl-fce(o-D-fructose. Preparation of the oxime followed by further acetylation gave the crystalline acetate of the oxime [ m.p. 207-208° Ca ]D - -118° (in chloroform)]. < The oxime of l,6-di-t>-trityl-D-fructose affords the same product on acetylation. The keto form was proved by formation of the crystalline diethyl dithioacetal from the acetyl derivative. 

The oximes of arabinose, rhamnose (Legay, 1952), and fructose (Bredereck et ai, 1956) display a weak band at 1653 cm, which may indicate the acyclic form, but it is possible that the N—H of the cyclic form... 

The glucose-lysine Amadori compounds monofructosy1-lysine and dlfructosy1-lysine have been Isolated, and the kinetics of their formation studied. 1-Deoxy-l-tolylamino-D-fructopyranose has been obtained by amlnatlon of fructose with g -toluldine, and shown to form an acyclic oxime and, on reaction with glycine ethyl ester, the glycosylamlne derivative (3). ... 

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