Total Synthesis Of Kigamicins And FD-594

Part 1: total synthesis of kigamicinsKigamicins are a class of polycyclic xanthone natural products containing an eight rings core skeleton,which constitutes A-E by linking different glycosyl groups for a total of five compounds.In the early stage,we tried to achieve the synthesis of kigamicin through the strategy of expanding the core skeleton of the three rings to both sides.Unfortunately,it has not been successful.However,on this basis,we have developed a strategy of coupling,asymmetric dihydroxylation,and oxidative coupling.By adopting a convergent synthetic route,we have realized the construction of the kigamicins eight rings skeleton.Part 2: total synthesis of FD-594FD-594 is a natural product of polycyclic xanthone natural product.Its unique structure has attracted our attention.We designed a convergent synthetic route,first prepared the coupled fragment,and successfully constructed the backbone of FD-594 through our developed coupling,asymmetric dihydroxylation,and oxidative coupling strategies.To remove the protection,we finally completed the synthesis of FD-594 aglycon in 17 steps with a total yield of 20%.On this basis,we constructed the glycosidic bond using the core skeleton and the trisaccharide fragment,and removed the protective group in two successive steps.We finally completed the total synthesis of FD-594 in 20 steps with a total yield of 2.7%..