Access to diarylmethanols by Wittig rearrangement of ortho-, meta- and para-benzyloxy-N-butylbenzamides

Abstract

The N-butyl amide group, CONHBu, has been found to be an effective promoter of the [1,2]-Wittig rearrangement of aryl benzyl ethers and thus allow the two-step synthesis of isomerically-pure substituted diarylmethanols starting from simple hydroxybenzoic acid derivatives. The method is compatible with a wide range of functional groups including methyl, methoxy and fluoro, although not with nitro and, unexpectedly, is applicable to meta as well as ortho and para isomeric series.