Kinetic Studies of Solvolysis. XV. Racemization Caused by the Molecular-Complex Formation in the Acetolysis of Optically Active 2,4,7-Trinitro-9-fluorenyl (+)-Camphor-10-sulfonate
作者:Kunio Okamoto、Issei Nitta、Haruo Shingu
DOI:10.1246/bcsj.41.1433
日期:1968.6
The complex formation has been examined by spectrophotometry or by the isolation of the crystalline complex of II. The acetolysis product, i.e., optically active 2,4,7-trinitro-9-fluorenyl acetate (III), has been racemized in the greater degree in the presence of the more aromatic hydrocarbons. This racemization is ascribed to the prolonged life of the SN1 ion-pair intermediate caused by the rapid equilibration
光学活性 2,4,7-trinitro-9-芴基 (+)-樟脑-10-磺酸酯 (II) 已通过 (+)-樟脑-10-磺酸对 9-重氮-2,4 的不对称攻击合成,7-三硝基芴。在 116–120°C 下添加菲、蒽和六甲苯可加速 II 的乙酰分解。这种加速归因于 II 和这些碳氢化合物之间分子复合物的形成。已通过分光光度法或通过分离 II 的结晶复合物来检查复合物的形成。乙酰解产物,即旋光的乙酸2,4,7-三硝基-9-芴酯(III),在更多芳烃的存在下被更大程度地外消旋化。这种外消旋化归因于未络合和络合的 SN1 中间体之间的快速平衡导致 SN1 离子对中间体的寿命延长;