Lindgren oxidation

{{Short description|Method for oxidizing aldehydes to carboxylic acids}}

{{Reactionbox

| Name = Lindgren oxidation

| Type = Organic redox reaction

| NamedAfter = Bengt O. Lindgren

| Section3 = {{Reactionbox Identifiers

| RSC_ontology_id = 0000287

}}

}}

Lindgren oxidation is a selective method for oxidizing aldehydes to carboxylic acids.{{cite journal | doi = 10.3891/acta.chem.scand.27-0888 | title = Preparation of Carboxylic Acids from Aldehydes (Including Hydroxylated Benzaldehydes) by Oxidation with Chlorite | year = 1973 | author = Lindgren, Bengt O. | journal = Acta Chemica Scandinavica | volume = 27 | pages = 888–890 | last2 = Nilsson | first2 = Torsten| doi-access = free }} The reaction is named after Bengt O. Lindgren.

The oxidation takes place in water containing solvent mixtures under slightly acidic conditions (pH 3–5) with sodium chlorite as oxidizer. To avoid complicated oxidation reactions the hypochlorite, which is formed in the reaction, has to be removed from the reaction mixture by scavengers. In the original publication, sulfamic acid and resorcinol were used. George A. Kraus and co-workers were the first to use 2-methyl-2-butene as scavenger under buffered conditions for the oxidation of an aliphatic and an α,β-unsaturated aldehyde.{{cite journal | doi = 10.1021/jo01312a004 | title = Synthetic studies toward verrucarol. 2. Synthesis of the AB ring system | year = 1980 | author = George A. Kraus; Bruce Roth | journal = The Journal of Organic Chemistry | volume = 45 | pages = 4825–4830 | issue = 24| url = https://lib.dr.iastate.edu/chem_pubs/792 }}{{cite journal | doi = 10.1021/jo01294a058| title = Model studies for the synthesis of quassinoids. 1. Construction of the BCE ring system | year = 1980 | author = George A. Kraus; Michael J. Taschner | journal = The Journal of Organic Chemistry | volume = 45 | pages = 1175–1176 | issue = 6| url = https://lib.dr.iastate.edu/chem_pubs/788 }} Later hydrogen peroxide also proved to work to remove the hypochlorite.{{cite journal | doi = 10.1021/jo00354a037 | title = Selective oxidation of aldehydes to carboxylic acids with sodium chlorite-hydrogen peroxide | year = 1986 | author = Enrico Dalcanale; Fernando Montanari | journal = The Journal of Organic Chemistry | volume = 51 | pages = 567–569 | issue = 4}}