Ribose 5- acetamido-5-deoxy

Acetamido-2-deoxy-D-arabinose 14 and 2-acetamino-2-deoxy-D-ribose 15 are prepared from (R)- and (S)-atrolactic acid derivatives respectively using the above reaction (8). 

The formation of these products from the dialkyl dithioacetals falls into two categories. The first group comprises compounds readily formed (or isolated), and is confined to derivatives of D-glucose, D-glucuronic acid, 2-acetamido-2-deoxy-D-glucose, and D-ribose. The products are obtained in high yield the formation is generally accomplished in aqueous solution, with one mole of mercuric chloride per mole of dithioacetal, and the solution is kept neutral. 

Springer and coworkers874 reported an extensive list of saccharides that were weakly inhibiting or noninhibiting. These included the 2-acetamido-2-deoxy derivatives of D-galactose, D-glucose, D-ribose, D-talose, and D-arabinose, 3,6-dideoxy-L- and -D-xy/o-hexose, L-lyxo-hexosulose, L-arabinose, D-fructose, and 2-deoxy-D-erythro-pentose. 

Amino-2-(leozy-D and L-rlbose derivatives 2-Acetamido-2-deoxy-/S-D-ribose 138-141 -69 -36 W 201... 

Acetamido-5-deoxy-D-ribose has been synthesized from benzyl 2,3-O-isopropylidene-)3-0-ribofuranoside through the sequence of the 5-0-p-tolylsulfonyl, 5-azido, and 5-acetamido derivatives. Hydrolysis of benzyl 5-acetamido-5-deoxy-2,3-0-isopropylidene-j8-D-... 

Derivatives of 4-acetamido-4-deoxy-D-ribose have been extensively investigated. Methyl 2-0-benzoyl-3,4-di-0-p-tolylsulfonyl-j8-L-ara-binopyranoside reacts with sodium azide to give, by selective replacement on C-4, methyl 4-azido-2-0-benzoyl-4-deoxy-3-0-p-tolylsuIfo-nyl-a-D-xylopyranoside. Methyl 4-acetamido-2-0-benzoyl-4-deoxy-... 

Mukaiyama and coworkers have pioneered many routes to the total syntheses of rare carbohydrates such as the 2-amino-2-deoxypentoses [75]. In 1982, they reported that the potassium enolate derived from the magnesium salt of the (/ )-atrolactic acid derivative 85 adds to 2,3-0-isopropylidene-D-glyceraldehyde in a highly stereoselective manner giving, after alcohol protection, imine hydrolysis and amine protection, the D-arabinopentoate derivative 86 (Scheme 13.35). Further elaboration leads to 2-acetamido-2-deoxy-D-arabinose 87. In a similar fashion, starting from (5 )-atrolactic acid, 2-acetamido-2-deoxy-D-ribose 88 was prepared [76]. 

Methyl ethers of 2-amino-2-deoxy-D-allose have been prepared in order to be subsequently degraded into methyl ethers of n-ribose. Methylation of methyl 2-acetamido-4,6-0-benzylidene-2-deoxy-o -D-alloside gave the 3-methyl ether, which, in turn, was hydrolyzed to afford methyl 2-acetamido-2-deoxy-3-0-methyl-a-D-allopyranoside. After partial methylation, a dimethyl ether, probably the 3,6, was isolated, whereas exhaustive methylation afforded the 3,4,6-trimethyl ether. An identical trimethyl ether was isolated after methylation of methyl 2-acetamido-3,4,6-tri-0-acetyl-2-deoxy-a-n-alloside. Hydrolysis of the methyl glycosides of both the 3-methyl and the 3,4,6-trimethyl ethers gave crystalline hydrochlorides, and the base of the former ether was characterized by means of its crystalline Schiff base with 2-hydroxynaphthaldehyde. 

Starting with methyl 3-acetamido-3-deoxy-2,4-di-0-(methylsulfonyl)-/3-L-xylopyranoside (96), Baker and Schaub" > > were able to obtain the D-ribose derivative (98) after prolonged refluxing. When the solvolysis of (96) was conducted in refluxing 95% ethanol, an intermediate was formed which was assumed to be the L-lyxose derivative (97) this could be converted into (98) by further reaction with sodium acetate in 2-methoxy-... 

Acetalation of the methyl P-furanoside of D-ribose with dimethoxymethane gave the new methylene derivative 3, whereas D-arabinose furnished the tri-C7-methoxymethyl ether 4 under the same conditions methyl p-D-arabinoside afforded a mixture of the two products 5 and 6. Treatment of L-sorbose with acetone and catalytic quantities of heteropolyacids HjPWjjO o or H4SiW,204o (0.1-0.35%) gave diacetonesorbose in 85% yield. The methyl glycoside monoacetonides 7 and 8 were obtained in the ratio 7 2 (90% combined yield) on exposure of 2-acetamido-2-deoxy-D-galactose to 2,2-dimethoxypropane and p-TsOH in dioxane at 60 °C When sucrose was heated in acetone... 

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