Abstract An alternative method for the preparation of 2′-bromo- (5b) and 2′-iodo- (5c) 1′,2′-unsaturated uracil nucleosides has been developed. The protocol was on the basis of the syn-elimination of pivalic acid from 2′-bromo-(7a,b) and 2′-iodo-(9a,b) 1′-pivaloyloxy-2′-deoxyuridine derivatives, which were derived from the halo-pivaloyloxylation of 3′,5′-bis-O-TBDMS-1′,2′-unsaturated uridine 1. Compounds 5b and 5c were shown to serve as versatile synthons for the respective 2′-C-branched 1′,2′-unsaturated uracil nucleosides, through palladium-catalyzed cross-coupling or halogen-lithium exchange reactions. Graphical Abstract

中文翻译：

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通过同步消除 2'-卤代-2'-脱氧-1'-新戊酰氧基尿嘧啶核苷的新戊酸合成 2'-卤代-1',2'-不饱和尿苷衍生物的替代方法：制备其 2' -C-支链核苷

摘要 已开发出一种制备 2'-溴-(5b) 和 2'-碘-(5c) 1',2'-不饱和尿嘧啶核苷的替代方法。该方案基于从 2'-溴-(7a,b) 和 2'-碘-(9a,b) 1'-新戊酰氧基-2'-脱氧尿苷衍生物中同步消除新戊酸，这些衍生物衍生来自 3',5'-双-O-TBDMS-1',2'-不饱和尿苷 1 的卤代新戊酰氧基化。 化合物 5b 和 5c 被证明可作为相应的 2'-C-支链 1' 的通用合成子,2'-不饱和尿嘧啶核苷，通过钯催化的交叉偶联或卤素-锂交换反应。图形概要