An Oxidation of Benzyl Methyl Ethers with NBS that Selectively Affords Either Aromatic Aldehydes or Aromatic Methyl Esters

Either mono- or dibromination of benzyl methyl ethers can be achieved by controlling the amount of NBS and the temperature. Elimination of methyl bromide from the monobrominated intermediates produces aromatic aldehydes, whereas hydrolysis of the dibrominated intermediates affords aromatic methyl esters in good yields.