caesium carbonate in N,N-dimethyl-formamide T=40°C; P=760.051 Torr; 15 h; Inert atmosphereGloveboxGreen chemistry;

1: 82 percent / pyridinium chlorochromate / CH2Cl2 / 7 h 2: 93 percent / NaOH / methanol / 4 h 3: 95 percent / NaCNBH3 / acetic acid / 7 h / Ambient temperature 4: 53 percent / n-BuLi / diethyl ether; hexane / 0.25 h / Ambient temperature View Scheme