1 - Amino-1 -deoxy-2-ketose derivatives

In a study of the reactions of sugars with amino-acids to give 1-amino-1-deoxy-ketose derivatives, malic acid was found to be the most efficient catalyst and pro-pane-l,2-diol the best solvent. ... 

Another possible mechanism7 for the transformation of sugars with amino acids into colored products is through the Amadori rearrangement,44 which is the isomerization of an aldosylamine to a ketose derivative, for example, of a D-glucosylamine derivative to a derivative of 1-amino-l-deoxy-D-fruc-tose. Such a conversion has been shown to occur when an amino acid reacts... 

Several 4-deoxy-4-nitro ketose derivatives have been synthesized. Three crystalline 2,7-anhydro-4-deoxy-4-nitro-/3-D-heptulopyranoses arose by nitromethane cyclization92 of the dialdehyde (74) produced by periodate oxidation of sedoheptulosan (73), and were assigned93 the D-alio (75), D-gulo (76), and D-altro (77) configurations by nuclear magnetic resonance spectroscopy of the corresponding, peracetylated amino sugars. When the cyclization of 74 was performed in methan-olic medium, a solid mixture of stereoisomeric nitronates was obtained in almost quantitative yield, and it could be partially separated into the individual nitronates, which furnished 75 and 76. The isomer 77... 

Hydrogenation of the ketose derivative (II) produces l-deoxy-l-(aryl-amino) sugar alcohols. Since a new asymmetric center is produced, two isomeric alcohols may be formed, but the yield of the two possible isomers is influenced greatly by the acidity of the medium employed for the hydrogenation (74). In acid solution, catalytic reduction of 1-deoxy-l-p-toluino-fructose (IV) takes place only in the aromatic ring (V) but in alkaline or neutral solution, it takes place with the formation of 1-deoxy-l-p-toluino-mannitol (p-tolyl-D-mannamine) (VI) ... 

The generic term monosaccharide (as opposed to oligosaccharide or polysaccharide) denotes a single unit, without glycosidic connection to other such units. It includes aldoses, dialdoses, aldoketoses, ketoses and diketoses, as well as deoxy sugars and amino sugars, and their derivatives, provided that the parent compound has a (potential) carbonyl gTOup. 

Tables V-LVII detail H and F shift and coupling information, and Tables LVIII to LXXI incorporate the C-n.m.r. data. The data within this compilation are arranged according to the following outline hexoses prior to pentoses, followed by anhydro sugars, sugar acids and lactones, amino sugars (and their synthetic, A -containing precursors), mono-, di-, and tri-deoxy sugars, branched derivatives, ketoses, polyfluorinated monosaccharides, and, finally, difluorinated amino sugars. Within this compilation, and even within each table, pyranoid derivatives are listed prior to their furanoid counterparts, hexoses prior to pentoses, functionalized prior to deoxy compounds the arrangement within each sub-table is made alphabetically.

Another class of pyrrole derivative may be obtained by the interaction of l-amino-l-deoxy-2-ketoses or 2-amino-2-deoxyaldoses with a jQ-dicarbonyl compound. Unlike the previous type (which is N-substituted), these pyrrole derivatives have a tetrahydroxybutyl group in the a- or /8-position with respect to the nitrogen atom of the ring, in addition to other groups arising from the dicarbonyl compound used in the condensation. The formation and reactions of this type of pyrrole derivative have been discussed in detail in two articles in this series48,49 they will, therefore, only be treated briefly. 1-Amino-l-deoxy-D-fructose (53) reacts with 2,4-pentanedione to give50 pyrrole derivative 54a similar pyrroles were obtained with ethyl acetoace-tate,50,51 which yields 54b. 

Like the iV-substituted glycosylamines, the JV-substituted 1-amino-l-deoxy-2-ketoses are colorless when the parent amine is colorless. 1-Deoxy-1-p-toluidino-D-fructose is tasteless, but derivatives of the more strongly basic amines are bitter. 

Extension and elaboration of the original nitromethane work continued to occupy the attention of Sowden and his collaborators until his death. A convenient synthesis of 2-deoxy-D-er2/f/tro-pentose was a particularly noteworthy achievement, and the substitution of 2-nitroethanol for nitromethane opened the door to the ketoses. The addition of sodium meth-oxide or ammonia to C-nitro-olefins also provided convenient means for preparing 2-0-methyl derivatives and 2-amino sugars, respectively. 

Glycosyl isothiocyanates have also been allowed to react with unprotected 2-amino-2-deoxyaldoses and 1-amino-1-deoxy-2-ketoses.68 This reaction leads to the formation of heterocyclic derivatives resulting from cy-clization involving the carbonyl group of the amino sugar moiety following the mechanistic pathway already discussed for similar condensation reactions with alkyl and aryl isothiocaynates. 

Amadori compounds, N-substituted 1-amino-l-deoxy-2-ketoses e.g. (1) in Scheme 1, formed by reaction of free sugars with the primary amino-groups in free amino acids, peptides or proteins can be determined by g.c. analysis of the A-(carboxymethyl)-amino acid derivatives e.g. (2) released by a protocol involving periodate oxidation of the sugar residue. ... 

Ketoses also react with both aliphatic and aromatic amines, and the derived ketosylamines (XXXIII) can also rearrange in a reverse of the Amadori rearrangement with the formation of a 2-amino-2-deoxy-aldose (XXXIV). 

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