Synthesis of Mono‑O‑alkylated Homo­oxa­calix­[3]­arene and a Protection–Deprotection Strategy for Homo­oxa­calix­[3]­arene

The regioselective synthesis of mono-O-alkylated homo­oxacalix­[3]­arene is accomplished for the first time. The synthetic route relies on two key steps: (i) a facile protection of two OH groups at the lower rim of the homo­oxacalix­[3]­arene and (ii) the deprotection of 9-anthrylmethyl groups via the Pd/C-catalyzed hydrogenation under atmospheric hydrogen. An efficient protection–deprotection strategy for the functionalization of homo­oxacalix­[3]­arene is presented.