1: With n-butyllithium; diisopropylamine in tetrahydrofuran; hexane T=-75°C; 2 h; 2: With iodine in tetrahydrofuran

trichlorophosphate; N,N-dimethyl-formamide T=90°C;

1: potassium carbonate; iodine / water / 100 °C 2: trichlorophosphate / N,N-dimethyl-formamide / 90 °C View Scheme

1.1: 2,2,6,6-tetramethylpiperidine; butyllithium / tetrahydrofuran; hexane / 2 h / -75 °C 1.2: 76 percent / iodine / tetrahydrofuran 2.1: 79 percent / butyllithium; diisopropylamine / tetrahydrofuran; hexane / 4 h / -75 °C 3.1: isopropylmagnesium chloride / tetrahydrofuran / 1 h / 0 °C 3.2: 67 percent / N-chlorosuccinimide / tetrahydrofuran / 1 h / 25 °C 4.1: diisopropylamine; butyllithium / tetrahydrofuran; hexane / 2 h / -75 °C 4.2: 81 percent / iodine / tetrahydrofuran View Scheme

1.1: isopropylmagnesium chloride / tetrahydrofuran / 1 h / 0 °C 1.2: 67 percent / N-chlorosuccinimide / tetrahydrofuran / 1 h / 25 °C 2.1: diisopropylamine; butyllithium / tetrahydrofuran; hexane / 2 h / -75 °C 2.2: 81 percent / iodine / tetrahydrofuran View Scheme

1.1: 79 percent / butyllithium; diisopropylamine / tetrahydrofuran; hexane / 4 h / -75 °C 2.1: isopropylmagnesium chloride / tetrahydrofuran / 1 h / 0 °C 2.2: 67 percent / N-chlorosuccinimide / tetrahydrofuran / 1 h / 25 °C 3.1: diisopropylamine; butyllithium / tetrahydrofuran; hexane / 2 h / -75 °C 3.2: 81 percent / iodine / tetrahydrofuran View Scheme

1: With lithium diisopropyl amide in tetrahydrofuran; hexane T=-75°C; 2 h; 2: With water; silica gel in hexane; dichloromethane

1.1: lithium diisopropylamide / tetrahydrofuran; hexane / 2 h / -75 °C 1.2: 26 percent / silica gel; H2O / CH2Cl2; hexane 2.1: tert-butyllithium / pentane; diethyl ether / 0.25 h / -75 °C 2.2: 79 percent / -78 °C View Scheme

copper(l) iodide in N,N-dimethyl-formamide T=100°C; 5 h; Sealed tube;

copper(l) iodide; fluorosulfonyl(difluoro)acetic acid methyl ester in N,N-dimethyl-formamide T=100°C; 5 h; Sealed tube;