1: sodium hydrogencarbonate / toluene / 22 h / 100 °C 2: hydrogenchloride; water; methanol / 1 h / 20 °C View Scheme

1: sodium hydrogencarbonate / toluene / 20 h / 100 °C / Inert atmosphere 2: tetrabutyl ammonium fluoride / tetrahydrofuran / 0.25 h / -20 °C / Inert atmosphere View Scheme

1: sodium hydrogencarbonate / toluene / 17 h / 100 °C / Inert atmosphere 2: hydrogenchloride; water; methanol / tetrahydrofuran / 6.5 h / 20 °C View Scheme

1: sodium hydrogencarbonate / toluene / 22 h / 100 °C 2: water; methanesulfonic acid / tetrahydrofuran / 72 h / 20 °C View Scheme

1: 52 percent / NaHCO3 / toluene / 42 h / 80 °C 2: 84 percent / K2CO3; MgBr2*Et2O; n-butanethiol / diethyl ether / 0.5 h / 20 °C 3: 86 percent / 4-N,N-dimethylaminopyridine / CH2Cl2 / 1 h / 20 °C 4: 100 percent / p-toluenesulfonic acid monohydrate / 1.75 h / 20 °C 5: 83 percent / aq. HCl / methanol / 0.75 h / 45 °C 6: 91 percent / CH2Cl2 / 1.25 h / 20 °C View Scheme

1: 19 mg / toluene / 4 h / 80 °C 2: 98 percent / tetrabutylammoonium fluoride / tetrahydrofuran / 3 h / 20 °C 3: 68 percent / polymer supported para-toluenesulfonic acid; 4 Angstroem molecular sieves / CH2Cl2 / 16 h / 20 °C 4: aq. HCl / methanol / 2 h / 40 °C 5: 3 mg / 4-N,N-dimethylaminopyridine / CH2Cl2 / 1 h / 20 °C View Scheme

1.1: PhLi / cyclohexane; diethyl ether; dioxane / 0.17 h / cooling 1.2: 78 percent / cyclohexane; diethyl ether; dioxane / 12 h / 20 °C 2.1: 96 percent / BF3*Et2O; Me2S / CH2Cl2 / 18 h / 20 °C 3.1: 95 percent / salcomine; O2 / dimethylformamide / 2 h / 20 °C View Scheme

in toluene T=70°C; 19 h;