lithium diisopropyl amide in tetrahydrofuran T=-78°C;

potassium hydride in tetrahydrofuran; N,N,N',N',N'',N''-hexamethylphosphoric triamide T=50°C; 1.5 h;

BF3*AcOH in dichloromethane T=0°C; 0.333333 h;

1: 89 percent / NaH 2: 84 percent / BF3-acetic acid / CH2Cl2 / 0.33 h / 0 °C View Scheme

1: 91 percent / dimethylsulfoxide; 1,2-dimethoxy-ethane 2: 89 percent / NaH 3: 84 percent / BF3-acetic acid / CH2Cl2 / 0.33 h / 0 °C View Scheme

1: 91 percent / 1.) sodium hydride / dimethylsulfoxide; 1,2-dimethoxy-ethane / 65 °C / 1.) 1 h; 2.) 1.5 h 2: 89 percent / sodium hydride / dimethylsulfoxide / 1 h / Ambient temperature 3: 84 percent / boron trifluoride*acetic acid / CH2Cl2 / 0.33 h / 0 °C View Scheme