1: 65 percent / potassium tert-butoxide / 2-methyl-propan-2-ol / 24 h / 90 °C 2: 1) TMEDA, n-BuLi / 1) in dry ether at reflux for 1h 2) CO2 as a continous stream for 1h 3: 1) SOCl2 4: 1) BF3*THF 2) NaOH, H2O2 / 1) for 1h 2) at 50 deg C for 1h 5: 95 percent / triethylamine / CH2Cl2 / -22 °C 6: 94 percent / LiBr / dimethylformamide 7: 84 percent / Mg / tetrahydrofuran 8: 72 percent / 4.5M HCl / H2O / 18 h / Heating View Scheme

potassium tert-butylate in tert-butyl alcohol T=90°C; 24 h;