Experimental Evidence for Nonstatistical Diradical Intermediates: Thermal Chemistry of Vinylcyclobutane Derivatives
Thermally activated carbon migrations have been reported for a number of hydrocarbon systems including vinylcyclopropanes and vinylcyclobutanes. Thorough understanding of this prior work is necessary to place in context the data that have been obtained in the course of this study. A [1,3] sigmatropic rearrangement has been observed in both bicyclic vinylcyclobutanes such as bicyclo[2.1.1]hex-2-enes and bicyclo[3.2.0]hept-2-enes, as well as monocyclic vinylcyclobutane derivatives. Because these compounds exhibit varying degrees of strain, comparisons between the reactivity of these compounds will reveal the effect of strain on the outcome of the thermal reorganization. In addition, the effect of changing substitution pattern on [1,3] sigmatropic shifts has been examined; specifically, methyl and deuterium have been used as stereochemical probes. Examination of the effects these substituents have on the course of the reaction has allowed insight into the mechanistic course of this rearrangement. The work presented herein, when compared to studies of related systems, will help to answer questions both about the importance of conformational flexibility as well as substitution pattern on the products formed in [1,3] sigmatropic rearrangements.
Franklin and Marshall College Archives, Undergraduate Honors Thesis 2006
- F&M Theses Collection