Study On The Asymmetric Synthesis Of Neolaxifolrins A And Trichloroisocyanuric Acid Mediated Synthsis Of The Chlorinated Oxindoles

Genus isodon is an important source of diterpenoid natural products,and becomes one of the research hotspots in organic chemistry.Neolaxiflorin A possesses a new diterpenoid skeleton bearing a chiral cyclopropane and 6/6/5 three ring systems.This thesis aimed on the synthesis of neolaxiflorin A,studied the construction of ring AB in neolaxiflorin A.At the same time,the preparation of 3,3-disubstituted chlorinated oxindoles derivatives by chlorination/cascade carbocyclization of N-arylacrylamide with trichloroisocyanuric acid was also investigated.This thesis consists of the following three parts: The chapter one: Research progress of diterpenoids from genus isodonIn this chapter,we gave a brief reviewabout recent new methods and strategies for the total synthesis of polycyclic diterpenoids,such as maoecrystal V,maoecrystal Z,maoecrystal P,longikarurin E,sculponeatin N and tricholabal A,which are isolated from the genus species.The chapter two: Asymmetric synthesis of neolaxiflorin AIn this chapter,we carried out the construction of ring AB in neolaxiflorin A with(+)-3-carene as starting material.In this investigation,we have tried several strategies to assemble the ring AB in neolaxiflorin A.Although all of them could not conquer the construction of the ring AB,these attempts provided important experiences for our later synthesis of this natural produt and its derivatives.The chapter three: Trichloroisocyanuric Acid Mediated Synthsis of the Chlorinated OxindolesIn this chapter,a metal-and additive-free strategy for preparation of chlorinated oxindoles has been achieved through a chlorine radical-induced cascade chlorination/carbocyclization of N-aryl acrylamides by using trichloroisocyanuric as radical initiator and chlorine source.