Synthesis of 1,3‐Oxazole‐Substituted 2‐Naphthols and Phenols From Their Corresponding Ethers via Claisen Rearrangement

We report the synthesis of 1,3‐oxazole‐substituted 2‐naphthols and phenols from aryl heterobenzyl ethers via Claisen rearrangement by employing a Lewis acid‐based ionic liquid as a promoter. Heterobenzyl‐2‐naphthyl ethers bearing electron‐donating and ‐withdrawing groups produced exclusively [3,3]‐sigmatropic Claisen rearranged products in excellent yields under the standard reaction conditions. Meanwhile, aryl heterobenzyl ethers bearing electron‐donating and ‐withdrawing groups produced a mixture of rearranged products via [1,3] or [3,3]‐Claisen or para ‐Claisen rearrangement. We also demonstrated a gram‐scale reaction for this methodology. The reported ionic liquid can be reused for the subsequent cycles.