1: 72 percent / K-Selectride / tetrahydrofuran / 5.5 h / -78 °C 2: POCl3; pyridine / 1 h / 20 °C 3: 250 mg / K2CO3 / methanol; H2O / 1 h / Heating 4: 37 percent / MnO2 / acetone / 12 h / 20 °C View Scheme