Type of Document	Dissertation
Author	Yang, Jingyue
Author's Email Address	jy05c@fsu.edu
URN	etd-03302011-173155
Title	Anionic Rearrangement of 2-Benzyloxypyridine Derivatives and a Synthetic Approach to Aldingenin B
Degree	Doctor of Philosophy
Department	Chemistry and Biochemistry, Department of
Advisory Committee	Advisor Name Title Gregory B. Dudley Committee Chair Igor Alabugin Committee Member Lei Zhu Committee Member Michael Shatruk Committee Member Thomas C. S. Keller III University Representative
Keywords	Anionic Rearrangement 2-Benzyloxypyridine Oxidative Ketalization Aldingenin B
Date of Defense	2011-03-17
Availability	unrestricted
Abstract [1,2]-Anionic rearrangements are important tools for altering the complexity of molecules at hand. In Part I of this dissertation, an anionic rearrangement of 2-benzyloxypyridine is described. Pyridine-directed metallation of the benzylic carbon leads to 1,2 migration of pyridine via a postulated associative mechanism (addition / elimination). Several aryl pyridyl carbinols were obtained in high yields. A formal synthesis of carbinoxamine, an antihistamine drug used for the treatment of seasonal allergies and hay fever, emerges from this methodology. As an update, the [1,2]-anionic rearrangement of benzyl 2-pyridyl ethers can also be accessed by a distinct and unusual mechanism: addition of alkyllithium reagents to α-(2-pyridyloxy)-styrene triggers anionic rearrangement to teriary pyridyl carbinols. This will be presented in Chapter 4 and the process is explained by invoking contraelectronic, pyridine-directed carbolithiation of the enol ether π-system. Part II of this dissertation is focused on a synthetic approach to aldingenin B. The synthesis of the tricyclic core of aldingenin B from a key internal alkyne was completed. Synthesis of alkynes by fragmentation is an on-going interest of the Dudley lab. One current goal is to apply our methodology in conjunction with an innovative oxidative alkyne ketalization to achieve a short and efficient synthesis of aldingenin B. The specific goal for this dissertation was to prepare a model alkyne by conventional methods and establish the feasibility of the oxidative alkyne ketalization. The preparation and selenium-mediated cyclo-ketalization of an alkyne-diol will be described as a model study for the synthesis of aldingenin B in Chapter 8. The oxidative cyclization is a simplifying transformation for aldingenin B, as it provides a convenient method for generating the tricyclic core of the natural product from a functionalized carbocycle. Some preliminary experiments to guide future efforts for completing the synthesis of aldingenin B will be presented in Chapter 9.
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