Base catalysed aromatic Claisen rearrangement of 3-hydroxyphenyl allyl ethers

Abstract

The 3-hydroxyphenyl allyl ethers (1a–d) have been shown to undergo rearrangement in refluxing aqueous methanolic potassium hydroxide in the presence of oxygen, whereas no reaction occurs in the absence of base and oxygen, and the products formed are the result of accelerated [3,3] sigmatropic processes in which moderate regioselection is operating; evidence is presented for the process being radical rather than anion mediated.