- SYNTHESIS; MOLECULAR CONFORMATION AND BIOLOGICAL ACTIVITY OF 6-AMINO-5-AZACYTIDINE
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Reaction of N-ethoxycarbonylguanidine II with 2,3,5-tri-O-benzoyl-β-D-ribosyl isocyanate (II) afforded N-ethoxycarbonylamidinourea IV, which was cyclized by bis(trimethylsilyl)acetamide to the 6-ethoxy derivative VII.Ammono- and methanolysis of intermedia
- Piskala, Alois,Hanna, Naeem B.,Zajicek, Jaroslav,Cihak, Alois
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p. 2502 - 2511
(2007/10/02)
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- The Synthesis of (R)-2',3'-Dihydroxypropyl 5-Deoxy-5-dimethylarsinyl-β-D-riboside, a Naturally Occurring Arsenic-Containing Carbohydrate
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The synthesis of the title compound, isolated from the brown kelp (Ecklonia radiata) or the giant clam (Tridacna maxima), is reported.Glycosidation of 1-O-acetyl-2,3,5-tri-O-benzoyl-β-D-ribose, either directly with (S)-1,2-di-O-benzylglycerol or via the derived orthoester with (S)-1,2-O-isopropylideneglycerol, led to two fully protected glycerol β-D-ribofuranosides.Subsequent chemical manipulations led to a common intermediate having a free hydroxy group at C 5 of the D-ribose residue.Replacement of this hydroxy group by a chlorine atom allowed the introduction of the dimethylarsinyl group at C 5 in a two-step procedure, and removal of protecting groups provided the natural product.
- McAdam, David P.,Perera, Anna M. A.,Stick, Robert V.
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p. 1901 - 1908
(2007/10/02)
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- THE SYNTHESIS OF (R)-2',3'-DIHYDROXYPROPYL 5-DEOXY-5-DIMETHYLARSINOYL-β-D-RIBOSIDE, A NATURALLY-OCCURING, ARSENIC-CONTAINING CARBOHYDRATE
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The synthesis of (R)-2',3'-dihydroxypropyl 5-deoxy-5-dimethylarsinoyl-β-D-riboside is reported.
- McAdam, David P.,Stick, Robert V.
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p. 251 - 254
(2007/10/02)
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- Syntheses and Structure Assignments of Six Azolinone Ribonucleosides
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N-Ribosidation of a series of azolinones was achieved via silylation and SnCl4 catalysis.N-Ribosidation of 4-imidazolin-2-one gave 1-β-D-ribofuranosyl-4-imidazolin-2-one; of 1,2,4-triazolin-3-one gave 2- and 4-β-D-ribofuranosyl-1,2,4-triazolin-3-one, and 2,4-di-β-D-ribofuranosyl-1,2,4-triazolin-3-one; and of 2-tetrazolin-5-one gave 1-β-D-ribofuranosyl-2-tetrazolin-5-one and 1,4-di-β-D-ribofuranosyl-2-tetrazolin-5-one.Structure assignments were based on NMR and mass spectra, microanalytical data, and interconversions.The triazolinone monoriboside isomer structures were differentiated by 13C NMR long-range coupling patterns, and the assignments were confirmed by X-ray crystallography.New syntheses were developed for several of the ribonucleosides by fashioning the azolinone rings from 2,3,5-tri-O-benzoylribofuranosyl isocyanate.
- Haines, David R.,Leonard, Nelson J.,Wiemer, David F.
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p. 474 - 482
(2007/10/02)
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