1: n-butyl-magnesium chloride With zinc dibromide in tetrahydrofuran T=-78 - 0°C; 2: 2-iodo-3-methyl-2-cyclopenten-1-one With bis-triphenylphosphine-palladium(II) chloride in tetrahydrofuran; N,N-dimethyl-formamide T=23°C; 2 h;

1-methyl-pyrrolidin-2-one; copper(l) iodide; triphenyl-arsane; bis(benzonitrile)palladium(II) dichloride T=100°C; 0.5 h;

1-methyl-pyrrolidin-2-one; copper(l) iodide; triphenyl-arsane; bis(benzonitrile)palladium(II) dichloride T=90°C; 0.333333 h;