SmI2-induced reductive cyclizations for the synthesis of cyclic ethers and applications in natural product synthesis

This tutorial review covers SmI2-induced reductive cyclizations of β-alkoxyacrylate, β-alkoxyvinyl sulfone, and β-alkoxyvinyl sulfoxide, as methods for efficient construction of cyclic ethers. These cyclizations were developed as tools to aid in the total synthesis of marine polycyclic ethers, whose complex, synthetically challenging structures and potent bioactivities have attracted the attention of numerous synthetic organic chemists. Applications of the methods to total syntheses of various natural products containing cyclic ether are also described.