1: 1-chloro-4-iodo-butane With chloro-trimethyl-silane; ethylene dibromide; zinc in tetrahydrofuran T=35 - 40°C; Metallation; 12 h; 2: With copper diacetate; lithium chloride in tetrahydrofuran T=0°C; transmetalation; 3: cyclohexenon With chloro-trimethyl-silane in tetrahydrofuran; diethyl ether T=-18°C; Addition;

bis(acetylacetonate)nickel(II); chloro-trimethyl-silane; 1,3-di[N,N-diethylaminomethyl]-1,2,2-trimethylpentane in tetrahydrofuran; acetonitrile T=20°C; 12 h;