CuI/n-Bu3P complex in tetrahydrofuran T=-45 - -35°C; 1 h;

1: (Z)-2-(tributylstannyl)vinyl cyanocuprate With boron trifluoride diethyl etherate in tetrahydrofuran T=-78°C; 0.0833333 h; 2: 3-methylcyclopent-2-en-1-one in tetrahydrofuran T=-78°C; 0.5 h; 3: With hydrogen iodide T=20°C;

copper(l) iodide; tributylphosphine in tetrahydrofuran T=-40 - -10°C; 4 h;

hydrogenchloride

1: 88 percent / TsOH*H2O / benzene / 6 h / Heating 2: 1) BH3*THF, 2) aq. NaOH, 35percent aq. H2O2 / 1) r.t., 30 min, 2a) < 40 deg C, 2b) 50 deg C, 1 h View Scheme