Studies Towards The Construction Of 6,6,5,7-Tetracyclic Skeleton Of Calyciphylline A–Type Daphniphyllum Alkaloids And Total Synthesis Of Paucidirinine

This thesis first studied the strategy to construct 6,6,5,7-tetracyclic skeleton of Calyciphylline A-type Daphniphyllum alkaloids which utilized[2+2]reaction of Staudinger ketene,provided a new strategy and idea for the Daphniphyllum synthesis.At the meantime,starting from commercial available tryptamine hydrochloride,using the cascade reaction of Diles-Alder reaction,intramolecular amidation and SmI₂promoted radical cyclization reaction as key step,we finished the total synthesis of Aspidofractinine indole alkaloid Paucidirinine with 8%overall yield and then conducted asymmetric synthesis studies of Pauciduridine.The full text contains the following three chapters:Chapter 1.Applications of Cycloadditions and Alkylations Based on Indole Skeleton（Review）.This chapter introduces various reactions forms of cycloadditions and alkylations which based on indole skeleton,while presents serveral examples concerns the synthesis application of those reaction.Finally we made prospect of future development of these reactions.Chapter 2.Studies towards Constructions of 6,6,5,7-Tetracyclic Skeleton of Calyciphylline A-type Daphniphyllum Alkaloid.This chapter introduces general information of Daphniphyllum alkaloid,and progress in synthesis of Daphniphyllum alkaloid,especially the Calyciphylline A-type Daphniphyllum alkaloid.On the basis of the previous work,a new strategy for synthesis of 6,6,5,7-tetracyclic skeleton is proposed.The classical Staudinger Ketene Cycloaddition and[2+2]reaction of allene and quaternary allene imine were also explored,this part of work is still under exploring.Chapter 3.Studies on Total Synthesis of Paucidirinine and Related Aspidofractinine Indole Alkaloids.A brief introduction of Aspidofractinine’s general information and review of previous synthesis works was first presented in this chapter,then we conduct our total synthesis using synthetic strategy which constructed the crucial scaffold of Paucidirinine via[4+2]cycloaddition,amidation and samarium diiodide-promoted radical cyclization.The asymmetric synthesis of Pauciduridine is now under studying.