Hydrolysis and intramolecular transesterification of ribonucleoside 3′-phosphotriesters:: the effect of alkyl groups on the general and specific acid-base-catalyzed reactions of 5′-O-pivaloyluridin-3′-yl dialkyl phosphates
Hydrolysis and intramolecular transesterification of ribonucleoside 3′-phosphotriesters:: the effect of alkyl groups on the general and specific acid-base-catalyzed reactions of 5′-O-pivaloyluridin-3′-yl dialkyl phosphates
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DOI：
10.1039/a707095k
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发表时间：
1998-03-01
期刊：
影响因子：
--
通讯作者：
Lonnberg, H
中科院分区：
文献类型：
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作者：
Kosonen, M;Hakala, K;Lonnberg, H
合成了5 ′-新戊酰基-2 ′-（四氢吡喃-2-基）尿苷-3 ′-基磷酸酯的二异丙酯、二乙酯、双（2-甲氧基乙基）酯和异丙酯。在酸性条件下除去2 ′-保护基，将所得的核糖核苷3 ′-磷酸三酯异构化成其2 ′-对应物，并将异构体混合物裂解成2 ′-和3 ′-磷酸二酯和2 ′，在氯化氢水溶液和几种缓冲溶液中，通过反相HPLC在从H-0 - 1.5至pH 8。测定了不依赖于缓冲液的部分反应的β（1g）值，以及缓冲液催化反应的β（1g）和Bronsted α和β值。各种部分反应的机制进行了讨论的基础上观察到的结构效应。
Diisopropyl, diethyl, bis(2-methoxyethyl) and isopropyl 2-methoxyethyl esters of 5'-pivaloyl-2'-(tetrahydropyran-2-yl)uridin-3'-yl phosphate have been prepared. The 2'-protecting group has been removed under acidic conditions, and the isomerization of the resulting ribonucleoside 3'-phosphotriester to its 2'-counterpart and the cleavage of the isomeric mixture to 2'- and 3'-phosphodiesters and a 2',3'-cyclic phosphate has been followed by reverse phase HPLC in aqueous hydrogen chloride and several buffer solutions over a wide acidity range from H-0 - 1.5 to pH 8. The beta(1g) values of the buffer-independent partial reactions, and the beta(1g) and Bronsted alpha and beta values of the buffer catalyzed reactions have been determined. The mechanisms of various partial reactions are discussed on the basis of the structural effects observed.