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The Amadori rearrangement of glycosylamine derivatives to l-desoxy-l-amino-2-ketose derivatives occurs (1) slowly in the solid state on storage at 25°and (2) rapidly in hot alcoholic solution in the presence of compounds containing active methylenic hydrogen atoms. These new conditions gave crystalline l-desoxy-l-amino-2-ketose derivatives from glycosyl derivatives of secondary alkylamines, of primary and secondary aralkylamines, and of a primary aromatic amine. 1-Desoxy-lpiperidino-D-fructose in aqueous solution with amino acids produced brown substances much more rapidly at 25°than did D-glucose or N-D-glucosylpiperidine at the same />H. The other desoxyaminoketoses also gave rapid browning reactions with amino acids. Since the Amadori rearrangement occurs spontaneously in N-glycosides in the dry state, and the products of the rearrangement undergo rapid browning reactions with amino acids, a mechanism for non-enzymatic browning in sugar-amine systems based on the Amadori rearrangement is proposed. I. The Amadori RearrangementThe isomerization of N-substituted glycosylamines (N-glycosides) to l-desoxy-l-amino-2-ketose (isoglucosamine) derivatives is known as the Amadori rearrangement. Amadori3 showed that, depending on the manner of heating of D-glucose with a primary arylamine, two different isomers, one labile and one stable, could be isolated. Kuhn, with Dansi,4 Weygand6 and Birkofer,6 identified Amadori's more labile isomer as the N-glucoside (I, R = aryl, R' = H) and the more stable isomer as an isoglucosamine derivative (II). Whereas both Amadori and Kuhn mentioned reaction conditions which did not involve the addition of acids, Weygand,7 in a critical review of the rearrangement conditions, was unable to obtain isoglucosamine derivatives consistently from N-D-glucosylarylamines unless catalytic amounts of acid were present.The Amadori rearrangement has been demonstrated to be general for glycosyl derivatives of primary aromatic amines6•7; however, it has been reported not to occur for glucosyl derivatives of piperidine,6•8 dibenzylamine,6 and alkylamines in general.9 Since we have recently shown10 that Kuhn and Birkofer's "dibenzylamine-N-glucoside''6 was actually 1-desoxy-l-dibenzylamino-D-fructose (II, R and R' = CeHsCHo--), the restriction of the occurrence of the rearrangement to only primary arylamine-N-glycosides11 is not valid. We have now found that the Amadori rearrangement occurs for glycosyl derivatives of piperidine, morpholine, diethanolamine and /3-phenylethylamine under new conditions that appear generally applicable to all types of glycosylamines.

As part of a program for the extended utilization of products from corn, a systematic study was made of the preparation of saccharic acid by the nitric acid oxidation of corn sugar. Saccharic acid can be prepared in a yield of 41% by oxidizing 1 mole of dextrose with 4 moles of concentrated nitric acid at 55°to 75°C. for 1 hour. After the removal of saccharic acid as its insoluble potassium acid salt, the by-product sugar acids formed in the oxidation may be converted to oxalic acid in a yield of 44% of theory.

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