Total synthesis of the cyclopeptide alkaloid sanjoinine G1 and its C-11 epimer

Abstract

The naturally occurring cyclopeptide alkaloid sanjoinine G1 and its C-11 epimer were synthesized in 18 steps from D-serine. The key steps in the synthesis were the formation of the alkylaryl ether linkage via an SNAr reaction with 4-fluorobenzonitrile and the macrocyclization to form the 14-membered ring using a modification of the Schmidt protocol involving an activated pentafluorophenyl ester.