Synthesis of 3-alkyl-2,5-dimethylfuran derivatives by indirect alkylation of 2,5-dimethylfuran with aliphatic nitrocompounds

Abstract

The preparation of 3-alkyl-2,5-dimethylfuranes via indirect alkylation of 2,5-dimethylfuran is reported. Thus, primary nitroalkanes react with cis-3-hexen-2,5-dione giving a tandem Michael addition/elimination of nitrous acid, followed by chemoselective hydrogenation of the C=C double bond of the obtained enones. The Paal-Knorr reaction, performed with p-toluenesulfonic acid in diethyl ether, completes the formation of the title compounds. In this context the nitroalkane can be considered as an alkyl cation synthon.