【作者】 刘志强；

【导师】 厍学功；

【作者基本信息】 兰州大学 ， 化学·有机化学， 2023， 硕士

【摘要】 本论文对灰烷二萜Mollactones A-C和Mollolide A及倍半萜Antroalbocin A进行了合成研究。全文包括以下三章。第一章[3.2.1]桥环构筑的策略及在萜类天然产物合成中的应用(综述)本章中,我们按照反应类型介绍了[3.2.1]桥环的构筑方法和策略,然后详细评述了其在二萜和倍半萜全合成中的应用进展。第二章Mollactones A-C和Mollolide A的合成探索本章中,我们首先简单介绍了Mollactones A-C及Mollolide A的结构和相关生源关系。然后,我们设计了三条路线来合成Mollactones A-C。在第一条路线中,我们以Pd催化的羰基α位去对称化烯基化作为关键反应构建其核心桥环骨架,但经过大量条件筛选没有成功。于是我们转向第二条路线,想尝试经5/5/3环系开环反应来构筑所需[3.2.1]桥环,但因中间体产率太低,难以进行后续合成探索。最终我们转向了第三条路线,在成功得到关键的三环体系后,后续工作正在进行中。第三章Antroalbocin A的合成研究本章中,我们首先简单介绍了Antroalbocin A的分离背景及相关合成研究工作。然后,我们从简单易得的2,4-二甲氧基苯甲醛出发,通过Pd/C还原,邻甲酰化,格氏试剂加成,选择性脱甲基和羟基的还原得到关键的反应前体,尝试了氧化去芳化的[5+2]环化反应来构建其核心骨架,但未取得成功。我们又尝试从邻甲酚出发通过几步官能团转化得到前体,继续尝试氧化去芳化的[5+2]环化反应,目前这部分工作仍在进行中。更多还原

【Abstract】 In this thesis,we mainly studied the synthesis of the grayanane diterpenes Mollactones A-C and Mollolide A and the sesquiterpene Antroalbocin A.It contains three chapters.Chapter 1 The advances of synthetic strategies toward bicyclic [3.2.1] skeleton and their applications in total synthesis of natural terpenoids(review)In this chapter,we introduce the construction methods and strategies of [3.2.1]bridge rings according to the type of reaction.Then we reviewed their applications in total syntheses of natural diterpenes and sesquiterpenes.Chapter 2 Synthetic studies towards Mollactones A-C and Mollolide AIn this chapter,we firstly summarized the structure characters and possible related biogenesis relationships between Mollactones A-C and Mollolide A.Then we designed three routes to synthesize Mollactones A-C.In the first route,we used a Pd-catalyzed desymmetric α-alkylation reaction of carbonyl compounds as a key reaction,but we didn’t obtain the desired bicyclic [3.2.1] product after extensive reaction conditions screening.So we turned to the second route and tried to build the required bicyclic[3.2.1] skeleton through a ring-opening reaction of the 5/5/3 tricyclic precursor.However,this route was soon abandoned due to the difficulties we met during the preparation of the required key intermediate.Eventually we moved on to the third route.And this time we successfully obtained the key tricyclic product.The follow-up work is underway.Chapter 3 Synthetic studies towards Antroalbocin AIn this chapter,we firstly introduced the the background and previous synthetic studies towards Antroalbocin A.Then starting from 2,4-dimethoxybenzaldehyde,we prepared the key precursor through a series transformations including Pd/C reduction hydrolysis,o-formylation,Grignard reagent addition,selective demethylation and reduction of the hydroxyl group.With the key precursor in hand,an oxidative dearomatization [5+2] cyclization was attempted without success.We also tried to obtain the reaction precursor from o-cresol through several functional group conversions and continue to exam the designed tandem oxidative dearomatization/ [5+2]cyclization reaction.This work will be carried out by other people in this lab.更多还原