Synthesis of trifluoromethylated dihydrofurans by addition of 1,3-dicarbonyl compounds to alkenes promoted by manganese(III) acetate

Radical addition reaction of trifluoromethyl-1,3-dicarbonyl compounds (1a-e) with various alkenes (2a-f) was investigated in the presence of manganese(III) acetate. As a result of these reactions trifluoromethyl ketone substituted dihydrofuran and bicyclic enol ether derivatives were obtained. A formation of dihydrofuran's mechanism was proposed for all compounds. Radical addition reactions with 1,1-disubstituted alkenes were obtained in good yields, however with cyclic alkenes were shown poor yields.