Many reactions produce carboxylic acids but are used only in specific cases or are mainly of academic interest.
* Disproportionation of an aldehyde in the Cannizzaro reaction
* Rearrangement of diketones in the benzilic acid rearrangement
* Involving the generation of benzoic acids are the von Richter reaction from nitrobenzenes and the Kolbe–Schmitt reaction from phenols.