pyridine; oxygen; palladium diacetate in toluene T=80°C; P=3800 Torr; 3 h;

sodium hexamethyldisilazane in tetrahydrofuran T=-78 - 20°C; 2 h;

1.1: tetrahydrofuran / 1 h / -78 °C 2.1: tetrahydrofuran / 1 h / -78 °C 2.2: 6.33 g / hydrochloric acid / -78 - 20 °C 3.1: 95 percent / sodium methoxide / methanol / 0.5 h / 0 °C 4.1: 94 percent / NaHMDS / tetrahydrofuran / 2 h / -78 - 20 °C View Scheme

1: 95 percent / sodium methoxide / methanol / 0.5 h / 0 °C 2: 94 percent / NaHMDS / tetrahydrofuran / 2 h / -78 - 20 °C View Scheme