Pauson-Khand反应是构建环戊烯酮结构的重要方法之一，由于分子内远距离的烯炔之间很难形成有效地络合，因而很少被用于合成大环化合物。本项目设计使用不饱和键连接的烯炔底物，通过不饱和键的络合作用使分子内远距离的烯炔之间顺利发生Pauson-Khand反应，从而实现大环化合物的制备并构建具有反Bredt规则 [n,2,1] 双环骨架。基于此方法，开展具有重要生理活性的双环[7,2,1]二萜类天然产物Shikoccin、O-Methylshikoccin、Epoxyshikoccin和O-(methylepoxy)shikoccin等的全合成研究工作。利用作为连接和配位基团的不饱和键，发生进一步的Conia-Ene反应或自由基环化反应，构建三环[7.2.1.0]三环骨架，开展二萜类天然产物Xerophinoid A、Longikaurin E和Trichorabdal A等的全合成研究。

Pauson-Khand reaction is widely applied in construction of cyclopentanone. However, this reaction is rarely employed in the synthesis of macrocyclic compounds, due to the lack of effective chelating between the remote enyne and catalyst. In this project, a new type of macrocyclic Pauson-Khand reaction is developed for the construction of anti-Bredt bicyclo[n.2.1] skeletons, which is realized by using inner carbon-carbon unsaturated bond as a tether and as well as a ligand. The total syntheses of bicyclo[7.2.1] diterpenoids with important biological activities (e.g. Shikoccin, O-Methylshikoccin, Epoxyshikoccin, and O-(methylepoxy)shikoccin) would be implemented based on this reaction. The tricyclo[7.2.1.0] framework could also be established by further derivatization of the unsaturated carbon-carbon of the resulted bicyclo[7.2.1]dodecene, employing Conia-Ene reaction or reductive radical cascade reaction. Then the total synthesis of structurally complex diterpenoids such as Xerophinoid A, Longikaurin E and Trichorabdal A could be accomplished via this strategy.