作为五味子家族天然产物的代表性成员，Pre-Schisanartanin C是一个结构复杂的降三萜类天然产物，其结构特点主要体现在：1.分子中具有独特的[5-5-7-8-3]环系结构，此为天然产物中首次报道；2.分子中含有12个手性中心，其中包含7个连续的手性中心以及3个季碳手性中心；3.该分子具有高度氧化的环萜类骨架（含9个氧原子），而且分子内具有的各种典型的环状结构集中体现了结构单元的多样性。.Pre-Schisanartanin C的结构特点引起了我们的兴趣：作为全合成目标分子，该分子结构复杂而新颖，因而极具挑战性；并且，该分子的结构为五味子家族天然产物的代表性结构之一，对它的全合成将为该家族天然产物的生物活性及生源途径研究做出贡献；此外，本实验室在完成Schindilactone A的过程中发展了一条普适性的合成路线，我们将在该分子的全合成中尝试实现该路线多样性导向的全合成。

Pre-Schisanartanin C, a representative member in Schisandraceae nature product family, is a novel nortriterpenoid which has a complicated structure. It is featured as: 1.It has a unique 5-5-7-8-3 polycyclic skeleton which is first reported among nature products. 2.It contains 12 stereo-centers including 7 continuous ones and 3 quarternary ones. 3.This molecule has a highly oxygenated cyclic terpenoid skeleton (which contains 9 oxygen atoms in its structure) and all these typical cyclic units show its structural variety..The structure features of Pre-Schisanartanin C attract our interest. As a synthetic target, its complicated and novel structure makes its total synthesis a challenge. Additionally, as Pre-Schisanartanin C is one of the representative members of the Schisandraceae nature product family, so, the total synthesis will make much contribution to the research of the bio-activity and bio-synthetic route of the entire nature product family. Moreover, our laboratory has developed a general synthetic route in the total synthesis of Schindilactone A, and we will attempt achieving this route's diverse-directed total synthesis in the total synthesis of Pre-Schisanartanin C.