1: 85 percent / anhydrous HCl / methanol / 12 h / 70 °C 2: 76 percent / tetrahydrofuran / 0.33 h / 22 °C 3: 81 percent / 1.) H2O2, BF3*Et2O / 3.) DMAP / 1.) CH2Cl2; 2.) CH2Cl2, 8 min, 23 deg C; 3.) CH2Cl2, 23 deg C, 18 h 4: 96 percent / LiOH / tetrahydrofuran; methanol; H2O / 1 h / 50 °C View Scheme

Multi-step reaction with 3 steps 1: 65 percent / MnO2 / CH2Cl2 / 23 h / 24 °C2: 98 percent / NaOMe / methanol / 1.25 h / 0 °C3: xylene / 5 h / Heating; variation of time  

Multi-step reaction with 2 steps 1: 85 percent / anhydrous HCl / methanol / 12 h / 70 °C2: 76 percent / tetrahydrofuran / 0.33 h / 22 °C  

Multi-step reaction with 5 steps 1: 85 percent / anhydrous HCl / methanol / 12 h / 70 °C2: 76 percent / tetrahydrofuran / 0.33 h / 22 °C3: 81 percent / 1.) H2O2, BF3*Et2O / 3.) DMAP / 1.) CH2Cl2; 2.) CH2Cl2, 8 min, 23 deg C; 3.) CH2Cl2, 23 deg C, 18 h4: 96 percent / LiOH / tetrahydrofuran; methanol; H2O / 1 h / 50 °C5: 66 percent / triethylamine, 1-((3-dimethylamino)-propyl)-3-ethylcarbodiimide hydrochloride / tetrahydrofuran / 18 h / 23 °C