Synthesis of 4,5-Dihydrofuran-3-carbonitrile Derivatives with Electron-Rich Alkenes in the Presence of Manganese(III) Acetate

Radical cyclization reactions mediated by manganese(III) acetate were carried out with ν‐excessive alkenes (2a‐d) and 3‐oxopropanenitriles (1a‐f) resulting in the formation of 3‐cyano‐4,5‐dihydrofuran derivatives in poor to high yields. A mechanism was proposed for the cyclization reaction. The significance of the study is the formation of the 3‐cyano‐4,5‐dihydrofuran derivatives resembling terfuran, 2‐(2‐thienyl)furan and 2‐(2‐benzofuryl)furyl compounds having the fluorescent properties due to a conjugated ν‐electron system particularly containing the cyano moeity. Radical cyclization reactions mediated by manganese (III) acetate were carried out with π‐excessive alkenes (2a‐d) and 3‐oxopropanenitriles (1a‐f) resulting in the formation of 3‐cyano‐4,5‐dihydrofuran derivatives in poor to high yields.