1.1: AlCl3, aluminium chloride / dichloromethane / 1.75 h / 30 - 40 °C / Inert atmosphere 1.2: Cooling with ice 2.1: AlCl3, aluminium chloride; 1,1,3,3-tetramethyldisiloxane / dichloromethane / 0 - 5 °C / Inert atmosphere 3.1: sodium tetrahydroborate; CuSO4‵5H2O; methanol / 0 - 5 °C / Inert atmosphere 3.2: N,N-dimethylaminopyride 4.1: sodium hydride / Inert atmosphere 4.2: 3 h / 110 - 115 °C / Autoclave View Scheme