1: 1-bromo-butane With magnesium; ethylene dibromide in 2-methyl tetrahydrofuran T=20°C; Inert atmosphere; 2: 2-acetyl-furan in 2-methyl tetrahydrofuran T=0 - 20°C; Grignard reaction; 1.75 h; Inert atmosphere; chemoselective reaction;

in diethyl ether Heating;