Pericyclizations of Conjugated Allenes and Other Polyenes

合成有机化学项目正在支持加州大学河滨分校化学系的威廉·H·冈村博士的工作。冈村博士正在开发可以在相对较低的温度下进行的热反应，从而快速有效地形成复杂的环系。这些将为现代农业和工业所需的复杂材料提供新的途径。本研究的目的是对手性共轭联烯和其他多烯参与碳-碳和碳-杂原子键形成周环反应的方式进行探索性的机理和合成研究。这项研究的意义在于，通过系统地评估导致新键形成的周环和其他聚烯反应，应该从机理和理论上对这些过程进行深入的了解。此外，详细了解取代基和取代模式如何影响周边化的立体机械过程，应该会为合成化学家提供如何更好地开发和设计合成方法的信息。目前提议的综合影响是，应该出现与合成手性多环构筑块有关的方法。这些主题包括对取代基对电环过程的pi表面立体选择性影响的理解的发展，以及对电环化的丙二烯变体、ı3，3！-Sigmatrotic位移和环加成过程的范围和局限性的探索。

+he Synthetic Organic Chemistry Program is supporting the work of Dr. William H. Okamura of the Department of Chemistry at the University of California at Riverside. Dr. Okamura is developing thermal reactions that can be carried out at relatively low temperatures that result in the rapid and efficient formation of complex ring systems. These will provide new routes to the complex materials needed in modern agriculture and industry. The purpose of the research is to carry out exploratory mechanistic and synthetic investigations on the manner in which chiral conjugated allenes and other polyenes participate in carbon-carbon and carbon-hetero atom bond forming pericyclization reactions. The significance of this study is that by systematically evaluating pericyclic and other reactions of polyenes that lead to new bond formation, both mechanistic and theoretical insight into these processes should obtain. Moreover, a detailed understanding of how substituents and substitution patterns affect the stereomechanistic course of pericyclizations should lend information to the synthetic chemist as to how to better develop and design synthetic methods. The synthetic impact of the current proposal is that methodology pertinent to the synthesis of chiral polycyclic building blocks should emerge. The topics include the development of an understanding of pi-facial stereoselectivity effects by substituents on electrocyclic processes and exploration of the scope and limitations of the allene variant of electrocyclizations, ı3,3!-sigmatropic shifts and cycloaddition processes.