Access to Diarylmethanols by Wittig Rearrangement of ortho-, meta-, and para- Benzyloxy- N-Butylbenzamides

J Org Chem. 2022 Apr 1;87(7):4692-4701. doi: 10.1021/acs.joc.1c03160. Epub 2022 Mar 14.

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.