1: methyllithium With copper(l) iodide in tetrahydrofuran; diethyl ether T=-78 - 0°C; 2: 3-Cyclopropyl-2-propinsaeure-methylester in tetrahydrofuran; diethyl ether T=-78°C; 1 h;

1: cyclopropyl-magnesium bromide With copper(l) iodide in tetrahydrofuran T=-65°C; 0.25 h; 2: methyl (Z)-3-phenylthio-2-butenoate in tetrahydrofuran T=-65°C; 3 h; Further stages.;

1.1: n-BuLi / diethyl ether / 1 h / -78 - 0 °C 1.2: 70 percent / diethyl ether / 4 h / 0 °C 2.1: CuI / diethyl ether; tetrahydrofuran / -78 - 0 °C 2.2: 78 percent / tetrahydrofuran; diethyl ether / 1 h / -78 °C View Scheme

in diethyl ether