Synthesis of ortho-Nitrophenols with an Ester Functionality via Nitro Rearrangement

Abstract

Although sigmatropic rearrangements have been widely reported, nitro group shifts have rarely been investigated. In this study, we investigated the synthesis of 4-ethoxycarbonyl-2-nitrophenols via the [1,3]-nitro shift. 4-Ethoxycarbonyl-4-nitrocyclohexanone, when subjected to I₂–DMSO system, gave the 4-nitrocyclohexa-2,5-dienenone intermediate that undergoes [1,3]-nitro shift followed by aromatization to afford 4-ethoxycarbonyl-2-nitrophenols. Although there is a room for improvement in product yield and selectivity, the development of a reaction system that facilitates [1,3]-nitro shift from readily available starting materials is noteworthy.

graphical abstract