Metal-catalyzed alkoxycarbonylation of a lactone

Abstract

The metal-catalyzed alkoxycarbonylation of a lactone is a method of alkoxycarbonylating a δ-lactone, specifically 3-ethylidene-6-vinyltetrahydro-2H-pyran-2-one. The method includes combining the δ-lactone with an alcohol in an organic solvent in the presence of a catalyst system that includes palladium or a salt thereof to form a reaction mixture, which is heated to 110-130° C. at a pressure of 20-50 bar for between 3-5 hours under flow of carbon monoxide gas. The product of the reaction is a substituted 2-octendioate diester. The alcohol may be methyl alcohol, n-butyl alcohol, 2-ethylhexanol, isobutyl alcohol, isopropyl alcohol, benzyl alcohol, or phenol. The solvent may be toluene, acetonitrile, or tetrahydrofuran. The method may include adding an acid to the reaction mixture, which may be dilute (about 5 mol %) sulfuric or p-toluenesulfonic acid. The catalyst system may also include a phosphine ligand.

Dependencies are inferred from the claim text.