The effects of substituents and solvent polarity oh photochemical [1,3] sigmatropic shifts. Experimental evidence in favour of the occurrence of sudden
作者:W.J.G.M. Peijnenburg、H.M. Buck
DOI:10.1016/s0040-4020(01)86197-4
日期:1988.1
experimental evidence regarding the occurrence of sudden polarization in acyclic alkenes is presented. It is shown that the yield of formation of the product derived from an intramolecular photochemical [1,3]-OH shift in 1 is dependent only on the polarity of the solvent employed. This result could be well explained in terms of a stabilization of the zwitterionic intermediate formed upon irradiation of 1 by reorientation
提供了有关在无环烯烃中突然极化的进一步实验证据。结果表明,分子内光化学[1,3] -OH的转变为1所生成的产物的产率仅取决于所用溶剂的极性。可以通过偶极溶剂分子的重新取向极化来稳定在辐射1时形成的两性离子中间体,从而很好地解释该结果。除此之外,发现在C 3 -C 9的末端碳原子处的烷基被取代。1中被苯基取代基形成的环外双键导致发生光化学[1,3] -H移位。取代基在环外双键上的这种指导作用可以在突然极化模型的基础上很好地解释。