【作者】 皋海涛；

【导师】 李卫东；

【作者基本信息】 兰州大学 ， 有机化学， 2011， 博士

【摘要】 第一章：综述了烯丙基硅官能团在仿生多烯环化路径合成天然产物过程中的应用,并对部分例子中的环化产物的立体化学控制作了简要的分析。第二章：主要包括三部分：(1)概括介绍了穿心莲内酯,包括其分离,结构鉴定,生理活性及合成研究等：(2)简要综述了Labdane型二萜的典型的合成方法；(3)描述了通过仿生多烯环化的策略首次不对称全合成穿心莲内酯的详细过程。整个全合成又包括三个阶段：(i)应用我们组发展的实用性的方法制备适当的手性环氧烯丙基硅环化前体；(ii)Lewis酸催化的仿生双环环化过程；(iii)侧链上带有独特的a位亚烷基的γ-丁内酯环基团的引入及全合成的完成。第三章：介绍了另一相反构型的Labdane型天然产物Rostratone的分离,结构及消旋体的合成。我们利用类似的策略,通过另外一个非对映的手性环氧烯丙基硅环化前体,首次完成了其仿生不对称全合成。更多还原

【Abstract】 This thesis aims at the asymmetric biomimetic total synthesis of two antipodal Labdane diterpenoids andrographolide and rostratone, which consists of the following three Chapters.Chapter 1:The application of the allylsilane functional group in the biomimetic polyene cyclization en route to natural products synthesis is reviewed, and the stereochemical controls of the cyclization product in some examples are briefly analyzed.Chapter 2:(1) General introduction on andrographolide, including the isolation, structural elucidation, biological activities, and synthetic studies, are summarized; (2) Typical synthetic approaches toward Labdanoids are briefly reviewed; (3) Details on the first enantioselective total synthesis of andrographolide by the biomimetic polyene cyclization strategy, is recorded, which involves the following three stages:(i) the assembling of the designated chiral epoxy allylsilane precursor via a practical protocol developed in our laboratory; (ii) the subsequent biomimetic bis-annulation mediated by Lewis acids; and (iii) the elaboration of the side-chain bearing a unique a-alkylidene y-butyrolactone unit and the completion of the total synthesis.Chapter 3:The isolation, structure, and racemic total synthesis of the antipodal Labdanoid rostratone are briefly summarized. The details of the first enantioselective biomimetic total synthesis of rostratone by an analogous approach from a diastereomeric chiral epoxy allylsilane precursor, is described.更多还原