1: With n-butyllithium in tetrahydrofuran; hexane T=-78°C; 1.5 h; Inert atmosphere; 2: With 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane in tetrahydrofuran; hexane T=-78 - 20°C; Inert atmosphere;

ammonium chloride in tetrahydrofuran; hexane; water; pentane

1: 2-(4-bromophenoxy)-2H-tetrahydropyran With n-butyllithium in tetrahydrofuran; hexane T=-78°C; 0.333333 h; Inert atmosphere; 2: tri-isopropoxy-borane in tetrahydrofuran; hexane T=-78°C; 1 h; 3: With hydrogenchloride in water T=25°C;

1.1: camphorosulfonic acid / CH2Cl2 / 24 h / 20 °C 2.1: n-BuLi / tetrahydrofuran; hexane / 3 h / -40 °C 2.2: B(OMe)3 / tetrahydrofuran; hexane / 18 h / 20 °C 2.3: 2.3 g / H2O / tetrahydrofuran; hexane / 2 h / 20 °C View Scheme

C4H9Li; HCl in tetrahydrofuran; hexane addn. of hexane soln. of butyllithium to THF soln. of benzene deriv. at -78°C, stirring for 20 min at -78°C under Ar, addn. of borate deriv., stirring for 1 h at -78°C, warming to room temp.; addn. of diethyl ether and water, addn. of aq. HCl to pH 7, separation of organic layer, extn. of aq. soln. (diethyl ether), evapn. of combined organic solns., chromy. (silica gel, toluene/acetone (4:1)), NMR;

1: 2-(4-bromophenoxy)-2H-tetrahydropyran With iodine; magnesium in tetrahydrofuran T=7°C; 1.83333 h; Inert atmosphereReflux; 2: boric acid trimethyl ester in tetrahydrofuran T=-14 - 0°C; 1.16667 h; Inert atmosphere;

1.1: camphorosulfonic acid / CH2Cl2 / 24 h / 20 °C 2.1: n-BuLi / tetrahydrofuran; hexane / 3 h / -40 °C 2.2: B(OMe)3 / tetrahydrofuran; hexane / 18 h / 20 °C 2.3: 2.3 g / H2O / tetrahydrofuran; hexane / 2 h / 20 °C View Scheme