The Total Synthesis Of Stemonine Alkaloids

Stemona alkaloids are the main components of the alkaloid family.In terms of molecular structure,stemona alkaloids generally have [1,2-b]pyrrolo[1,2-a]azepine as the core structure.The substitutions at different positions on the core scaffold afford various complex structures.Meanwhile,this class of molecules often exhibits many important biological activities such as anti-tuberculosisantibacterial,anti-fungal,anti-cancer and anthelmintic resistance.The research for the total synthesis of the stemona alkaloids lays a solid foundation for further research and development of this kind of alkaloids.At the same time,stemona alkaloids possess a unique structure,which provide ideas for chemists to develop new synthetic methodology and strategies.Therefore,the total synthesis of this kind of natural product has attracted the attention of many synthetic chemists,and it becomes a hot field of the natural product research.This thesis is divided into four parts: The first part introduces the research background,research ideas and research contents of the subject,and summarizes the research progress of the total synthesis of alkaloids in recent years.In the second part,we studied the synthesis of natural product parvistemonine A by retrosynthetic analysis of the structure of parvistemonine A.The synthetic route was designed using Scifinder software.The racemic synthesis of natural product parvistemonine A was completed by12 steps from 2,5-dimethoxytetrahydrofuran and ethyl 4-aminobutyrate hydrochloride and we introduced the problems encountered in the synthesis work and solutions.In the third part,we aimed to solve the construction of chiral center in the above part of work and redesign the synthetic route.Finally,the asymmetric synthesis of natural product parvistemonine A was completed using L-glutamic acid as chiral pool through 13 steps.In thefourth part,we tried to synthesize the natural product bisdehydronestemonine based on the above synthesis work.Some previous work has been completed,and the key reaction conditions have been explored,which lays the foundation for the subsequent synthesis.