著者
山根 晃 井上 英夫 上田 亨
出版者
The Pharmaceutical Society of Japan
雑誌
Chemical and Pharmaceutical Bulletin (ISSN:00092363)
巻号頁・発行日
vol.28, no.1, pp.157-162, 1980-01-25 (Released:2008-03-31)
参考文献数
12
被引用文献数
10 19

Treatment of 4-thiouridine with phenacyl bromide, bromoacetone, and ethyl bromoacetate gave the corresponding 4-thioalkylcarbonyl derivatives. The sulfur extrusion reactions of these compounds afforded ribosides of 4-phenacylidene-2 (3H)-pyrimidinone, 4-acetonylidene-2 (3H)-pyrimidinone, and 2-pyrimidinone-4-acetic ester, respectively. The ease of sulfur extrusion depends on the electron-withdrawing ability of the carbonyl group attached to the 4-S-methylene group. Sulfur extrusion reactions starting from 6-thioinosine similarly gave the ribofuranosides of 6-phenacylpurine and 6-acetonylpurine. These purine ribosides exist meinly as the enol form rather than the keto form.
著者
山根 晃 松田 彰 上田 亨
出版者
The Pharmaceutical Society of Japan
雑誌
Chemical and Pharmaceutical Bulletin (ISSN:00092363)
巻号頁・発行日
vol.28, no.1, pp.150-156, 1980-01-25 (Released:2008-03-31)
参考文献数
13
被引用文献数
13 26

Treatment of 6-methylsulfonyl-9-(2, 3, 5-tri-O-benzoyl-β-D-ribofuranosyl) purine with ethyl acetoacetate and sodium hydride in tetrahydrofuran afforded, after deblocking, 6-ethoxycarbonylmethyl-9-β-D-ribofuranosylpurine. Similarly, replacement of the 6-methylsulfonyl moiety with other carbanions derived from diethyl malonate, ethyl cyanoacetate, malononitrile, nitromethane, and sodium cyanide gave the corresponding 6-C-substituted purine nucleosides. Most of these derivatives exist as the 6-(1H)-exomethylene tautomeric forms. 6-Ethoxycarbonylmethylpurine riboside was further converted to 6-methyl, ethyl, propyl, butyl, and pentyl-purine ribosides by decarboxylation or prior alkylation of the methylene group followed by de-carboxylation. This reaction sequence facilitated the preparation of hitherto almost inaccessible alkyl or C-substituted purine nucleosides.