The facile synthesis of dihydrofurans by the oxidation of olefins with tris(2,4-pentanedionato)manganese(III)

Abstract

Eleven olefins were oxidized with tris(2,4-pentanedionato)manganese(III) at the reflux temperature to give the corresponding 3-acetyl-2-methyl-4,5- dihydrofurans in good yields. The oxidation of 9-benzylidene-9,10- dihydroanthracene under the same reaction conditions did not produce the corresponding dihydrofuran, but 9-[α-(1-acetyl-2-hydroxy-1-propenyl) benzylidene]-9,10-dihydroanthracene. When 1,1-diphenylethene was oxidized at room temperature, 3-acetyl-2-hydroperoxy-2-methyl-5,5-diphenyltetrahydrofuran was obtained in a high yield. The effects of the solvent and the additives on the yield of dihydrofuran, the comparable reactivities of other (2,4-pentanedionato)metal complexes, such as Co(III), Cr(III), Fe(III), and Cu(II), and the reaction mechanism are discussed. © 1985 The Chemical Society of Japan.