An efficient convergent strategy for the construction of a trans-fused 6-6-6-6-membered tetracyclic ether ring system was developed. The key steps involve coupling of two cyclic ethers by esterification, SmI2-promoted intramolecular reductive cyclization of iodo ester to hemiacetal, dehydration to dihydropyran, hydroboration, oxidation, intramolecular acetalization, and Lewis-acid catalyzed silane