1: 1.) n-BuLi, hexamethylphosphoramide (HMPA) / 1.) hexane, 5 deg C, 30 min, 2.) RT, overnight 2: p-toluenesulfonic acid / methanol / 1.5 h 3: 48 percent / Li, 1,3-diaminopropane, potassium tert-butoxide / 2 h 4: 86 percent / pyridinium dichromate (PDC) / dimethylformamide / 9 h View Scheme

1: 80 percent / liq. NH3, HMPA / 1) -70 deg C, 3h, 2) RT, overnight 2: 1) n-BuLi / 1a) Et2O, cyclohexane, 0 deg C, 1h, 1b) RT, 30 min, 2a) 1h, 0 deg C, 2b) 1h, RT 3: 90 percent / p-TsOH / methanol / Ambient temperature 4: NEt3 / CH2Cl2 / 1) 0 deg C, 30 min, 2) RT, 2h 5: 73 percent / LiBr / tetrahydrofuran / 2 h / Heating 6: 1) Mg / 1) Et2O, 2) Et2O, RT, overnight 7: 90 percent / Bu4NF / tetrahydrofuran / 0.17 h / Ambient temperature 8: p-TsOH / methanol / 10 h / Ambient temperature View Scheme

1.1: Mg / tetrahydrofuran / 20 °C 1.2: Li2CuCl4 / tetrahydrofuran / -78 °C 1.3: 55 percent / tetrahydrofuran / 17 h / -78 - 20 °C 2.1: 90 percent / pyridinium p-toluenesulfonate; ethanol / 3 h / 50 °C 3.1: 96 percent / N,N-(dimethylamino)pyridine / CH2Cl2 / 16 h 4.1: Mg / tetrahydrofuran / 20 °C 4.2: Li2CuCl4 / tetrahydrofuran / -78 °C 4.3: 64 percent / tetrahydrofuran / 15 h / -78 - 20 °C View Scheme

Multistep reaction;

Multistep reaction;

1: 1.) Mg / 1.) Et2O, reflux, 2 h, 2.) r.t., 3.5 h 2: 1.) Mg / 2.) Li2CuCl4 / 1.) Et2O, reflux, 2 h, 2.) THF, 0 deg C, 3 h 3: 94 percent / PPh3, Br2 / CH2Cl2 / 36 h / Ambient temperature View Scheme

1: 2-[(11-bromoundecyl)oxy]tetrahydro-2H-pyran With magnesium in tetrahydrofuran T=50°C; 2 h; Inert atmosphere; 2: 4,4'-bis-(chloromethyl)-biphenyl With dilithium tetrachlorocuprate in tetrahydrofuran T=0°C; 3 h; Inert atmosphere;

1: 2-[(11-bromoundecyl)oxy]tetrahydro-2H-pyran With magnesium in tetrahydrofuran T=50°C; 2 h; Inert atmosphere; 2: 4,4'-bis (bromomethyl)-biphenyl With dilithium tetrachlorocuprate in tetrahydrofuran T=0°C; 3 h; Inert atmosphere;

1.1: magnesium / tetrahydrofuran / 3 h / 55 °C 1.2: dilithium tetrachlorocuprate(II) / tetrahydrofuran / 3 h / 0 °C 2.1: 4.2 g / pyridinium p-toluenesulfonate / methanol / 3 h / Heating View Scheme

1: 91 percent / CuLi2Cl4 / tetrahydrofuran; diethyl ether / 0 °C 2: 80 percent / p-toluenesulfonic acid monohydrate / methanol 3: 60 percent / pyridinium dichromate / CH2Cl2 / 18 h / Ambient temperature View Scheme