Development of synthetic methodologies directed towards the generation of five membered ring allenes

Algı, Fatih
Chemists have always been fascinated by the cumulated diene system of allenes with its extraordinary properties such as the axial chirality of the elongated tetrahedron and a higher reactivity than non-cumulated C-C double bonds. The equilibrium geometry for an allene is linear with orthogonal pairs of substituents. An allene incorporated into a carbocyclic ring of nine or more carbon atoms is relatively unstrained. However, if the ring size is decreased, the linear perpendicular allene will be twisted and bent until, at some point, the energy gained by pi bonding in the two double bonds will be insufficient to offset the increased strain. Furthermore, ring constraints will exert torsion toward a planar arrangement of ligands. Therefore, one of the fundemantal questions is the influence of ring size on the barrier to pi bond rotation. Herein we wish to unveil a review of our research related to desperately seeking for five membered ring allenes such as, cyclopenta-1,2-diene (1) and some of its derivatives, e.g. 2, and 3. Furthermore, we will address a simple, mild and efficient method for the reduction of 1,4-benzoquinones 4 to corresponding hydroquinones 5.


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Citation Formats
F. Algı, “Development of synthetic methodologies directed towards the generation of five membered ring allenes,” Ph.D. - Doctoral Program, Middle East Technical University, 2006.