The α-Effect in the Stereochemistry of Kinetic Ketonization of Enols<sup>1</sup><sup>,</sup><sup>2</sup>
作者:Howard E. Zimmerman、Pengfei Wang
DOI:10.1021/jo034732w
日期:2003.11.1
organic reactions. Protonation occurring from the less hindered side of the, e.g., enolic system affords the less stable of two diastereomers. However, one apparent discrepancy has been in the synthesis of prostaglandins. The present research deals with the source of this behavior. A curious effect of the substituent at the enolic alpha carbon was uncovered. In certain instances an alpha substituent is
烯醇盐和其他强烈离域的阴离子物质的质子化的立体选择性的动力学控制涉及大量的有机反应。从例如烯醇体系的较少受阻侧发生的质子化提供了两种非对映异构体的较不稳定性。但是,前列腺素的合成存在一个明显的差异。本研究处理这种行为的来源。未发现烯醇α碳上取代基的奇怪作用。在某些情况下,迫使α取代基扭曲成构象,从而从其侧面阻断质子供体,从而逆转了质子化的立体化学。在这项研究过程中,研究了许多不同结构的五环烯醇。最后,对酮化反应过程进行了理论研究。