Hydrogermylation of 5-Ethynyluracil Nucleosides: Formation of 5-(2-Germylvinyl)uracil and 5-(2-Germylacetyl)uracil Nucleosides

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• 作者：Yong Liang ; Jean-Philippe Pitteloud ; Stanislaw F. Wnuk
• 刊名：The Journal of Organic Chemistry
• 出版年：2013
• 出版时间：June 7, 2013
• 年：2013
• 卷：78
• 期：11
• 页码：5761-5767
• 全文大小：306K
• 年卷期：v.78,no.11(June 7, 2013)
• ISSN：1520-6904

文摘

A stereoselective radical-mediated hydrogermylation of the protected 5-ethynyluracil nucleosides with trialkyl-, triaryl,- or tris(trimethylsilyl)germanes gave (Z)-5-(2-germylvinyl)uridine, 2鈥?deoxyuridine, or ara-uridine as major products. Reaction of the 尾-triphenylgermyl vinyl radical intermediate with oxygen and fragmentation of the resulting peroxyradical provided also 5-[2-(triphenylgermyl)acetyl]pyrimidine nucleosides in low to moderate yields. Thermal isomerization of the latter in MeOH occurred via a four-centered activated complex, and subsequent hydrolysis of the resulting O-germyl substituted enol yielded 5-acetyluracil nucleosides in quantitative yield.