6- Deoxy-L-glucose

Phenylalanine-derived oxazolidinone has heen used in O Scheme 52 as a chiral auxiliary for as)rmmetric cross-aldolization (Evans-aldol reactions [277,278,279,280,281,282,283,284, 285]). The 6-deoxy-L-glucose derivative 155 has heen prepared by Crimmins and Long [286] starting with the condensation of acetaldehyde with the chlorotitanium enolate of O-methyl glycolyloxazohdinethione 150. A 5 1 mixture is obtained from which pure 151 is isolated by a single crystallization. After alcohol silylation and subsequent reductive removal of the amide, alcohol 152 is obtained. Swem oxidation of 152 and subsequent Homer-Wadsworth-Emmons olefination provides ene-ester 153. Sharpless asymmetric dihydroxylation provides diol 154 which was then converted into 155 (O Scheme 60) (see also [287]). 

Occurrence. L-Quinovose (6-deoxy-L-glucose, 42) is a rare sugar found as its phenazine ester in a marine actinomycete.215 It was also tentatively identified in a lipopolysaccharide of Legionella feeleii.216... 

Note N-Aceylneuraminic add = sialic acid, abequose = 3,6-dideoxygalactose, rhamnose = 6-methyl-6-deoxy-L-glucose. 

The diastereoselective hydroxyl-directed cyclopropanation shown in Scheme 22 was one of a number studied which proceed with high stereoselectivity. The chiral auxiliary could be removed as indicated, and use of the equivalent derivative of 6-deoxy-L-glucose gave the enantiomeric cyclopropylmethanols.l 13... 

The multi-enzyme system was recently utilized for the synthesis of dTDP-4-keto-6-deoxy-a-D-glucose 3 and dTDP-P-L-rhamnose 5 generating dlTP from dTMP by dTMP kinase and acetate kinase [66, 71]. Further combination with GerB, a dTDP-4-keto-6-deoxy-D-glucose aminotransferase, gave dTDP-4-amino-4,6-dideoxy-D-glucose [72]. 

Acetamido-2-deoxy-D-glucose is a component of a mucopolysaccharide hyaluronic acid. It has been demonstrated, by PET imaging with the corresponding F labeled compound, that this glucose derivative is incorporated into the connective tissue at the interface of a tumor and healthy tissue. Thus, it can be used as a tumor label. 6-[ F]-6-Deoxy-L-ascorbic acid also deserves attention, as it maintains the antioxidant properties of ascorbic acid. Thus, it can be useful to smdy the biochemical... 

A mutant strain of Escherichia coli Y-10, defective in L-rhamnose synthesis, accumulates109 a considerable amount of thymidine diphosphate sugars. Three of them were identified110 as the esters of thymidine 5 -pyrophosphate with 6-deoxy-a-D-xyZo-hexopyranos-4-ulose (28), 6-deoxy-D-glucose, and D-fucose. The fourth component was found to be a 4-acetamido-4,6-dideoxy-D-galactose derivative111,112 (29) it occurs also in Pasteurella pseudotuberculosis102 and its... 

Rh = rhamnose = 6-deoxy-L-mannose (QHijOj) Ru = mtinose = 6-O-D-glucose... 

The difference between the behavior of the 6-amino-6-deoxy-D-glucose and -L-idose derivatives can be rationalized as follows. In the transition states for the formation of the 3,6-anhydro ring from the Tt-gluco isomers, the oxygen (or hetero) atoms attached to C-4 and C-5 are in a sterically unfavorable, cis relationship. The transition states from the h-ido amines involve a trans relationship of these hetero atoms. Thus, for the D-gluco amine, deamination reactions other than 3,6-anhydro ring-formation compete more effectively. 

The protonated amino group, however, has no nucleophilic activity, and does not form a hemiacetal an amino sugar can, therefore, be obtained, as a salt, in an otherwise unfavorable form. For example, 6-amino-6-deoxy-L-sorbose can be isolated as the hydrochloride of a furanose form (22) (presumably a). In alkaline solution, immediate ring-expansion to the pyranose form (23) occurs127 this reaction can be reversed under strongly acidic conditions. 4-Amino-4,6-dideoxy-D-glucose hydrochloride forms a 35 65 mixture of the a- and / -pyranose forms in solution.128... 

The metabolism of free L-fucose (6-deoxy-L-galac-tose), which is present in the diet and is also generated by degradation of glycoproteins, resembles the Entner-Doudoroff pathway of glucose metabolism (Eq. 17-18). Similar degradative pathways act on D-arabinose and L-galactose.60... 

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