1: 90 percent / CrO3-2Pyr / CH2Cl2 / 0.25 h / 23 °C 2: 92 percent / n-butyllithium / tetrahydrofuran / 1) 40 min, -78 deg C, 2) -78 to 0 deg C, 80 min 3: 78 percent / acetic acid / acetonitrile; H2O / 2.5 h / 23 °C / at pH= 4.5 6: acetonitrile / 12 h / 60 °C 7: 65 percent / n-butyllithium / tetrahydrofuran; hexamethylphosphoric acid triamide / 1) 1h, -78 deg C, 2) 2.5 h, -78 to 0 deg C 8: 75 percent Spectr. / 1.5M aq. K2CO3 / methanol / 24 h / 55 °C View Scheme