and freshly distilled benzaldehyde (20.8 mL, 21.8 g, 206 mmol, 4.0 equiv.) were dissolved in EtOH (175 mL). The mixture was cooled down to 5 °C using an ice/water-bath and a solution of KOH (7 M, 176 mL) mixed with EtOH (75 mL) was added dropwise through a dropping funnel. After complete addition, the mixture was allowed to warm up to RT and stirred for 18 h.