Gold-catalyzed cyclization of alkyne alcohols: Regioselective construction of functionalized 6,6- and 6,7-bicyclic ethers

Abstract

We describe an efficient regioselective formation of six-/seven-membered cyclic ethers based on goldcatalyzed intramolecular hydroalkoxylation. Sequential gold-catalyzed cyclization and palladium-catalyzed cross-coupling reactions afforded 6,6-bicyclic ethers, while reversing the reaction sequence (cross-coupling then cyclization) afforded 6,7-bicyclic ethers. This methodology should provide access to a range of functional polycyclic ethers.