Studies On Total Synthesis Of Dimeric Azaphilonoids Chaetoglobins A And B

Azaphilonoid represents a large natural polyketide family,which features with a common unqiue conjugated polyenone bicyclic core and a wide range of biological activities.However,very limited advances have been achieved in modern medicinal research.Chaetoglobins A and B were first isolated from Chaetomium globosum by Tan's group at Nanjing University.They have novel structure and biological activities,such as inhibition of human breast cancer cell line MCF-7 and colon cancer cell line SW116.Chaetoglobins A and B both belong to the azaphilone-type compounds,which contain a highly oxygenated bicyclic core and 2 chiral quaternary centers.Sheng Wang of this group successfully finished the total synthesis of Chaetoglobin A via a key "aryl-aryl oxidative coupling",and the absolute configuration was confirmed by Dr.Qiu at SIOC by single-crystal analysis.This thesis studied on the total synthesis of Chaetoglobin A,focusing on the asymmetric aryl-aryl oxidative coupling.We designed "intramolecular and intermolecular" rections and explored the possibility of asymmetric coupling.Now,we can obtain the biaryl product with up to 62%ee.Further work will be continued to the final asymmetric total synthesis in this laboratory.