diisobutylaluminium hydride in toluene T=-95°C;

Dess-Martin periodane in pyridine; dichloromethane T=23°C; 2 h;

1: 86 percent / Et3N, SO2Cl2 / toluene / -50 deg C, 1 h, 23 deg C, 16 h 2: 89 percent / diisobutylaluminum hydride / tetrahydrofuran / 23 h / 23 °C 3: 90 percent / Dess-Martin periodinane / pyridine; CH2Cl2 / 2 h / 23 °C View Scheme