1: pyridine / tetrahydrofuran / 1 h / 25 °C 2: diisobutylaluminum hydride / hexane; toluene / 1 h / 25 °C 3: imidazole / dimethylformamide / 1 h / 25 °C 4: 45 percent / tetra-n-butylammonium periodate / CH2Cl2 / 1 h / 25 °C 5: 74 percent / tetra-n-butylammonium fluoride / tetrahydrofuran / 0.25 h / 25 °C View Scheme

pyridine in tetrahydrofuran T=25°C; 1 h; Yield given;