potassium hydroxide in tetrahydrofuran; water T=80°C; 16 h;

1: 1) diisopropylamine, butyllithium, 2) HMPT / 1) THF, hexane, -78 deg C, 1 h, 2) THF, hexane, -78 deg C - room temperature 2: tetrahydrofuran; hexane / 0 °C 3: pyridinium tosylate / methanol / 5 h / 50 °C View Scheme