Efficient Synthesis of trans-Fused Polycyclic Ethers Including Tetrahydropyrans and Oxepanes Based on SmI2-Induced Reductive Cyclization

An efficient method for the synthesis of trans -fused polycyclic ether ring systems including tetrahydropyrans and oxepanes, i.e., six−seven−six-, six−seven−seven-, and six−seven−seven−six-membered polycyclic ether ring systems, was developed on the basis of SmI 2 -induced reductive intramolecular cyclization.