Studies Toward The Total Synthesis Of Rubriflordilactone B

This thesis aims at the total synthesis of rubriflordilactone B.It consists of the following three chapters.Chapter 1: This chapter describes research progress of nortriterpenoids,including the brief introduction of Schisandraceae natural products and the summary for synthetic strategy of nortriterpenoids.In particular,vinylogous Mukaiyama aldol reactions are discussed in detail.Chapter 2: It is divided into two parts.The substrates derived from tetrahydronaphtho[2,3-b]furan-2-ones which could be synthesized according to a Ni-promoted cyclization method developed by our lab,were served as a model for the investigatons to vinylogous Mukaiyama aldol(VMA)reaction.Next,concise synthesis of the DEFG ring system in Rubriflordilactone B had been successfully achieved,where radical 1,5-H abstraction/cyclization and VMA reaction play key roles.At the same time,we also tried other methods to improve stereoselectivities.Chapter 3: Attemped asymmetric total synthesis of Rubriflordilactone B was designed on the basis of previous progress.Starting from chiral bisindanol that could be prepared by cheap cyclopentadiene,an advanced intermediate containing DEF ring system in rubriflordilactone B has been obtained,which paved the way for the total synthesis of this challenging molecule.