OXYGEN SCRAMBLING AND STEREOCHEMISTRY DURING THE TRIFLUOROETHANOLYSIS OF OPTICALLY-ACTIVE 2-BUTYL 4-BROMOBENZENESULFONATE
OXYGEN SCRAMBLING AND STEREOCHEMISTRY DURING THE TRIFLUOROETHANOLYSIS OF OPTICALLY-ACTIVE 2-BUTYL 4-BROMOBENZENESULFONATE
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DOI：
10.1021/ja00169a035
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发表时间：
1990-06-20
影响因子：
15
通讯作者：
WOJCIECHOWSKI, M
中科院分区：
文献类型：
--
作者：
DIETZE, PE;WOJCIECHOWSKI, M
结果表明，在非桥连氧中含有 180 个 2-丁基 4-溴苯磺酸酯的三氟乙醇解过程中，会发生氧标记的扰乱。当对映体富集的 4-溴苯磺酸 2-丁基酯经历相同的溶剂解条件时，没有观察到起始酯的外消旋化。因此，如果离子对中间体参与三氟乙醇分解反应，则该离子对具有足够的寿命以允许阴离子旋转，从而导致氧扰乱。然而，不会发生会导致外消旋化的阳离子旋转。讨论了氧扰乱可能是协同反应并且不涉及离子对中间体的可能性。
It is shown that during the trifluoroethanolysis of 2-butyl 4-bromobenzenesulfonate, containing 180 in the nonbridging oxygens, scrambling of the oxygen label occurs. When enantiomerically enriched 2-butyl 4-bromobenzenesulfonate is subjected to the same solvolysis conditions, racemizationof the starting ester is not observed. Therefore if an ion-pair intermediate is involved in the trifluoroethanolysis reaction, the ion pair has a sufficient lifetime to permit rotation of the anion leadingto oxygen scrambling. However, rotation of the cation, which would lead to racemization, does not occur. The possibility that the oxygen scrambling may be a concerted reaction and not involve an ion-pair intermediate is discussed.