1: 1.) NaH / 1.) DMF, -40 deg C, 0.75 h, 2.) DMF, a) from -40 to -30 deg C, 0.75 h, b) RT, 4 h 2: 71 percent / potassium t-butoxide / CH2Cl2 / 1.5 h / Ambient temperature 3: 40 percent / HCl / CH2Cl2; methanol / 0.75 h / Ambient temperature View Scheme

1: 1.) NaH / 1.) DMF, -40 deg C, 0.75 h, 2.) DMF, a) from -40 to -30 deg C, 0.75 h, b) RT, 4 h 2: 71 percent / potassium t-butoxide / CH2Cl2 / 1.5 h / Ambient temperature 3: 75 percent / diisopropylethylamine / tetrahydrofuran / 4.5 h View Scheme