Ribofuranose 5- acetamido-5-deoxy

For synthesis of nucleosides, methyl 4-acetamido-2,3-di-0-benzoyl-4-deoxy-a-D-ribopyranoside (198c), obtained from 198a, was trans-formed by acetolysis into 4-acetamido-l,5-di-0-acetyl-2,3-di-0-benzoyl-4-deoxy-D-ribofuranose (199b). Either with preliminary treatment with hydrogen chloride in acetyl chloride, or directly, in the presence of titanium tetrachloride, 199b gave with chloromercuri-(6-... 

Benzyloxycarbonyl)amino]-5-deoxy-D-ribopyranose (208) was separable into its two anomers. In accordance with the above concept, the a-D anomer shows an upward mutarotation and a negative plain curve, whereas the )8-d anomer exhibits a downward mutarotation and a positive plain curve. A further deviation from the Hudson isorotation rule is observable with 4-acetamido-l-0-acetyl-4-deoxy-2,3,5-tri-0-p-nitrobenzoyl-/8-D-ribofuranose. ... 

In this synthesis, a mixture of tri-0-acetyl sugars was obtained, from which the desired 2-acetamido-l,3,5-tri-0-acetyl-2-deoxy-D-ribofuranose was isolated. Another sugar, assumed to be the isomeric 2-acetamido-l,3,4-tri-0-acetyl-2-deoxy-D-ribo-pyranose, was also isolated, converted to the O-acylglycosyl chloride, and allowed to react with chloromercuri-6-chloropurine. Deblocking with dimethylamine gave a nucleoside thought to be 9-(2-acetamido-2-deoxy-oi-D-ribopyranosyl)-JV ,W -dimethyl-adenine. 

Acetamido-l,2,5-tri-0-acetyl-3-deoxy-p-D-ribofuranose, A-330 5-Acetamido-2,3,4-tri-0-acetyl-5-deoxy-p-D-ribopyranose, A-332... 

O -Benzoyl-1,2- O -isopropylidene-3-O-methyl-a-D-ribofuranose, 1-73 5- 0 -Benzoyl-1,2- 0 -isopropylidene-a-L-ribofuranose, 1-73 5- 0 -Benzoyl-1,2- 0 -isopropylidene-a-D-ribofuranose, 1-73 5- 0 -Benzoyl-1,2- 0 -isopropylidene-3-0 -tosyl-a-D-ribofuranose, 1-73 Benzyl 5-acetamido-5-deoxy-2,3-0-isopropylidene-p-D-ribofuranoside, A-332... 

Acetamido-l,4,6-tri-0-acetyl-3-deoxy-a-D-mannopyranose, A-313 3-Acetamido-l,2,5-tri-0-acetyl-3-deoxy-p-D-ribofuranose, A-330 3-Acetamido-l,2,4-tri-0-acetyl-3-deoxy-5-thio-a-D-xylopyranose, A-352 3-Acetamido-l,2,4-tri-0-acetyl-3,6-dideoxy-a-L-glucopyranose, A-381 3-Acetamido-l,2,4-tri-0-acetyl-3,6-dideoxy-p-L-glucopyranose, A-381 3-Acetamido-l,4,6-tri-0-acetyl-2,3-dideoxy-a-D-/ xo-hexopyranose,... 

Fusion procedures have also been used to prepare nucleosides of 3-nitro-l,2,4-triazole and ethyl 4-nitropyrazole-3-carboxylate. Epimerization at C-2 occurred during the fusion of 3-acetamido-l,2,5-tri-0-acetyl-3-deoxy-j8-D-ribofuranose with 2,6-dichloropurine, yielding some a- and )3-D-arabinofuranosyl derivatives in addition to the expected products. ... 

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