One-Step Synthesis of -Symmetric Resorcin[4]arene Tetraethers.

The three-component reaction between a resorcinol, 1,3-dimethoxybenzene, and an alkyl aldehyde (R = C-C) along with BF·OEt affords a -symmetric resorcin[4]arene tetraether in one step; in most cases, the single isomer can be precipitated from the reaction mixture in moderate to excellent yields (up to 89%). The reaction is tolerant of 2-substituted resorcinols (R' = OH, Cl, Br, Me), allowing a third type of functionality to be regioselectively incorporated during the macrocyclization.