One-pot migration-formylation of benzyl aryl ethers under Duff reaction condition

A one-pot migration-formylation of benzyl aryl ethers under Duff reaction condition is described. The reaction was performed with HMTA (hexamethylene tetramine) and TFA (trifluoroacetic acid). Under the optimal reaction conditions, a variety of Bn and PMB ethers underwent ortho rearrangement.