hydrogenchloride in tetrahydrofuran; methanol T=20°C; 1 h;

1.1: conc. hydrochloric acid / tetrahydrofuran; methanol / 1 h / 20 °C 2.1: 1.4 g / pyridine; dimethylaminopyridine / 12 h / 20 °C 3.1: 87 percent / AD-mix-β; methanesulfonamide / 2-methyl-propan-2-ol; H2O / 50 h / 20 °C 4.1: pyridine / CHCl3 / 3 h / 20 °C 5.1: 1.8 g / K2CO3 / methanol; H2O / 15 h / 20 - 40 °C 6.1: aq. hydrobromic acid / CHCl3; acetic acid / 1.5 h / 20 °C 6.2: 44 percent / tributyltin hydride; α,α'-azobis(isobutyronitrile) / benzene / 1 h / Heating View Scheme

1: conc. hydrochloric acid / tetrahydrofuran; methanol / 1 h / 20 °C 2: 1.4 g / pyridine; dimethylaminopyridine / 12 h / 20 °C 3: 87 percent / AD-mix-β; methanesulfonamide / 2-methyl-propan-2-ol; H2O / 50 h / 20 °C 4: pyridine / CHCl3 / 3 h / 20 °C 5: 1.8 g / K2CO3 / methanol; H2O / 15 h / 20 - 40 °C View Scheme