1: 50 percent / EtO2*BF3 / CH2Cl2 / Ambient temperature 2: 95 percent / sodium methoxide / 4 h / Ambient temperature 3: LiHMDS / tetrahydrofuran / 0 °C 4: 85 percent / 1.) 1N NaOH; 2.) HCl; 3.) Dowex50xB View Scheme