- Facile Synthesis of 2'-Deoxy-3'-keto- and 2'-Deoxypseudouridine Derivatives and Analogues. Palladium(II)-Mediated Coupling Reactions of Furanoid Glycals
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C-Nucleosides, of either α or β configuration, are formed selectively in a palladium-mediated coupling reaction between furanoid glycals and (1.3-dimethyl-2,4-dioxo-1,3-dihydropyrimidin-5-yl)mercuric acetate.Control of anomeric configuration is accomplished by suitable choice of substituents for glycal 3-O- and 5-O-hydroxy groups; attack of organopalladium reagent and glycosidic bond formation occurs on the least sterically hindered face of the glycal ring.Removal of substituents from the coupled products yielded 2'-deoxy-3'-keto C-nucleosides, which upon metal hydride reduction produced the corresponding 2'-deoxy C-nucleosides.
- Cheng, Jane Chi-Ya,Hacksell, Uli,Daves, G. Doyle
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p. 3093 - 3098
(2007/10/02)
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- Nucleosides. 121. Improved and General Synthesis of 2'-Deoxy C-Nucleosides. Synthesis of 5-(2-Deoxy-β-D-erythro-pentofuranosyl)uracil, -1-methyluracil, -1,3-dimethyluracil, and -isocytosine
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5-(2-Deoxy-β-D-erythro-pentofuranosyl)-1,3-dimethyluracil (6a), -1-methyluracil (6b), -uracil (6c), and -isocytosine (6d) were synthesized.Compounds 6b-d are C-nucleoside isosteres of thymidine, 2'-deoxyuridine, and 2'-deoxycytidine, respectively. 1,3-Dimethylpseudouridine (1a), 1-methylpseudouridine (1b), pseudouridine (1c), and pseudoisocytidine (1d) were treated with 1,3-dichloro-1,1,3,3-tetraisopropyldisiloxane in pyridine to afford the corresponding 3',5'-tetraisopropyldisiloxanyl derivatives 2 which were converted into the respective 2'-O- C-nucleosides 3.Compounds 3a,b were converted directly into the corresponding 2'-deoxy β-C-nuleosides 5a,b exclusively by reduction with n-Bu3SnH.For the synthesis of 2'-deoxy β-C-nucleosides 5c,d, the intermediates 3c,d were trimethylsilylated prior to n-Bu3SnH treatment.Deprotection of 5a-d was effected by treatment with n-Bu4NF, and the corresponding free 2'-deoxy β-C-nucleosides 6a-d were obtained in good yields.
- Pankiewicz, Krzysztof,Matsuda, Akira,Watanabe, Kyoichi A.
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p. 485 - 488
(2007/10/02)
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