1: n-butyl 2-pyridyl telluride With Me2Cu(CN)Li2 in tetrahydrofuran; diethyl ether T=-20°C; 1.5 h; 2: cyclohexenon in tetrahydrofuran; diethyl ether T=20°C; 20 h;

in diethyl ether T=0°C;

1.1: Te / hexane; tetrahydrofuran / 0.17 h / 20 °C 1.2: 61 percent / hexane; tetrahydrofuran / 92 h / Heating 2.1: Me2Cu(CN)Li2 / diethyl ether; tetrahydrofuran / 1.5 h / -20 °C 2.2: 41 percent / diethyl ether; tetrahydrofuran / 20 h / 20 °C View Scheme

1.1: Te / hexane; tetrahydrofuran / 0.17 h / 20 °C 1.2: 70 percent / hexane; tetrahydrofuran / 92 h / Heating 2.1: Me2Cu(CN)Li2 / diethyl ether; tetrahydrofuran / 1.5 h / -20 °C 2.2: 41 percent / diethyl ether; tetrahydrofuran / 20 h / 20 °C View Scheme

1.1: Te / hexane; tetrahydrofuran / 0.17 h / 20 °C 1.2: 62 percent / hexane; tetrahydrofuran / 92 h / 20 °C 2.1: Me2Cu(CN)Li2 / diethyl ether; tetrahydrofuran / 1.5 h / -20 °C 2.2: 41 percent / diethyl ether; tetrahydrofuran / 20 h / 20 °C View Scheme