Unexpected regioselective synthesis of 5,17-dibromo-11,23-dihydroxycalix[4]arene hexyl ether

Abstract
Using transmetallation, quenching with B(OCH3)3, and oxidation regioselectively upper-rim functionalized dibromodihydroxycalix[4]arene hexyl ether was synthesized from p-bromocalix[4]arene hexyl ether in good yield.