Multi-step reaction with 2 steps 1: 93 percent / pyridine / 12 h / 0 °C2: 91 percent / dimethylsulfoxide / 2 h / 90 °C  

Multi-step reaction with 2 steps 1: 1.) 1 M diisobutyl aluminium hydride; 2.) 3N HCl / 1.) CH2Cl2, -5 deg C, 1.25 h, 2.) ether, water, 5-10 deg C, 2 h2: 93 percent / Et3N / CH2Cl2 / 3 h