Mannolide A和Cephalotanin A是近来从三尖杉科植物中分离得到的两种萜类天然产物。Cephalotanin A被发现对与炎症、哮喘、心脏病和多种癌症病理紧密相关的NF-kB信号通路有良好的抑制作用。在分子结构上，两个天然产物都具有九个手性中心，并分别具有六个和七个环系，形成了复杂且拥挤的多环空间结构。本项目拟通过具有手性环戊烯和α-吡喃酮单元化合物的分子内Diels-Alder反应为存在于多个三尖杉萜类天然产物中的笼状骨架发展一种简洁的不对称构建策略，并以此为基础实现Mannolide A和Cephalotanin A的首次不对称全合成，为其深入的生理活性以及构效关系研究奠定基础。

Mannolide A and cephalotanin A are two terpenoids isolated from Cephalotaxaceae plants recently. Cephalotanin A displays excellent inhibition activity to NF-kB pathway, which is tightly related to pathologies of phlegmonosis, asthma, cardiac disease and multiple kinds of cancers. Structurally, these two natural products both have nine chiral stereocenters, and six or seven ring systems, forming complex and congested spatial structures. Through intramolecular Diels-Alder reactions of compounds containing chiral cyclopentenes and α-pyrones, this project is going to develop an asymmetric construction strategy to the cage skeleton existing in multiple Cephalotaxus terpenoids. On the basis of the strategy, the first asymmetric total syntheses of mannolide A and cephalotanin A will be accomplished and build a foundation for the further studies on their physiological activities and structure-activity relationships.