- Total synthesis of pseudouridine: Via Heck-type C-glycosylation
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The reaction of 2,4-dimethoxy-5-iodopyrimidine (8) and 3,5-di-O-tert-butyldimethylsilyl protected ribofuranoid glycal 4 was carried out with Pd(OAc)2 as the catalyst, PPh3 as the ligand and Et3N as the base in DMF at 70 °C followed by desilylation to afford exclusively the β-anomer of 5-(2,3-dideoxy-3-oxoribofuranosyl)-2,4-dimethoxypyrimidine (11) in a very good yield. The subsequent protecting group and functional group interconversions furnished pseudouridine (Ψ, 1).
- Yu, Cheng-Ping,Chang, Hsin-Yun,Chien, Tun-Cheng
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p. 8796 - 8803
(2019/06/14)
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- Conversion of 2-deoxy-D-ribose into 2-amino-5-(2-deoxy-β-D-ribofuranosyl)pyridine, 2′-deoxypseudouridine, and other C-(2′-deoxyribonucleosides)
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The synthesis of 2-amino-5-(2-deoxy-β-D-ribofuranosyl)pyridine 2a, 2-amino-5-(2-deoxy-α-D-ribofuranosyl)-pyridine 23, 2-amino-5-(2-deoxy-β-D-ribofuranosyl)-3-methylpyridine 2b, 2-amino-5-(2-deoxy-α-D-ribofuranosyl)-3-methylpyridine 29 and 5-(2-deoxy-β-D-ribofuranosyl)-2,4-dioxopyrimidine [2′-deoxypseudouridine] 30a is described. These C-nucleosides are prepared either from 2-deoxy-3,5-O-(1, 1, 3, 3-tetraisopropyldisiloxan-1,3-diyl)-D-ribofuranose 15 or from 2-deoxy-3,5-O-(1,1,3,3-tetraisopropyldisiloxan-1,3-diyl)-D-ribono-1,4-lactone 16, which are themselves prepared from 2-deoxy-D-ribose 13. The sugar derivatives are first allowed to react with the appropriate 5-lithio-pyridine or 5-lithio-pyrimidine derivatives, which are prepared from 5-bromo-2-(dibenzylamino)pyridine 12a, 5-bromo-2-[bis(4-methoxybenzyl)amino]pyridine 12b, 5-bromo-2-dibenzylamino-3-methylpyridine 25 and 5-bromo-2,4-bis(4-methoxybenzyloxy)pyrimidine 33. The products from the reactions between the lithio-derivatives and the lactol 15 are cyclized under Mitsunobu conditions; the products from the reactions between the lithio-derivatives and the lactone 16 are first reduced with L-Selectride before cyclization, also under Mitsunobu conditions, In all cases, the β-anomers of the protected C-nucleosides are the predominant products. Finally, the separation of the α- and β-anomers and the removal of all of the protecting groups are described.
- Reese, Colin B.,Wu, Qinpei
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p. 3160 - 3172
(2007/10/03)
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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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- Pyrimidine to pyrimidine transformation process
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There is provided a novel process for pyrimidine to pyrimidine transformations by the displacement of the 1,2,3-portion of a pyrimidine by a 1,3-ambident nucleophile. The novel process requires that the 1 and 3 nitrogens of the pyrimidine moiety be substituted. The novel process makes available, inter alia, novel uracils, simple methods of radioisotopically labeling pyrimidine nuclei, a simple and inexpensive method of preparing the important antiviral and antileukemic material pseudoisocytidine and its new active analog 2'-deoxypseudoisocytidine.
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