Date of Graduation
Eberly College of Arts and Sciences
Bjorn C G Soderberg
Cyclobutenediones have proven useful as starting materials for synthesis of highly functionalized biologically relevant molecules. The rearrangement of cyclobutendiones has a wide synthetic scope and can be utilized as a key step in the construction of quinones, benzo[o]isoxazoles, and 3-methylenoxoindoles having a variety of substitution patterns. Construction of these molecules involves thermolysis of 4-hydroxy-2,4-di-aryl-2-cyclobutenones derived from squaric acid ester. In each of the cases the mechanism proceeds through an initial ring opening of the cyclobutene to afford a ketene intermediate that subsequently undergoes a ring closure with various intermolecular nucleophiles. This methodology has been utilized in the construction of an ellipticine model system.
Fisher, Kimberly Denise, "Thermal rearrangement of 4-aryl-4-hydroxy-2-cyclobuten-1-ones and application of the methodology in the formation of benzofuronaphthoquinones and benzocarbazolequinones" (2008). Graduate Theses, Dissertations, and Problem Reports. 4372.