sodium hydroxide; water in tetrahydrofuran T=20°C; 2 h;

1.1: 89 percent / Ph3P; Huenig's base / CH2Cl2 / 5 h / 20 °C 2.1: piperidine / ethyl acetate / 1 h / 20 °C 2.2: 85 percent / SiO2 / ethyl acetate 3.1: 83 percent / NaOH; H2O / tetrahydrofuran / 2 h / 20 °C View Scheme

1.1: 65 percent / dimethylformamide / 3 h / 40 - 50 °C 2.1: 68 percent / Et3N / benzene / 20 - 40 °C 3.1: 89 percent / Ph3P; Huenig's base / CH2Cl2 / 5 h / 20 °C 4.1: piperidine / ethyl acetate / 1 h / 20 °C 4.2: 85 percent / SiO2 / ethyl acetate 5.1: 83 percent / NaOH; H2O / tetrahydrofuran / 2 h / 20 °C View Scheme

1.1: 68 percent / Et3N / benzene / 20 - 40 °C 2.1: 89 percent / Ph3P; Huenig's base / CH2Cl2 / 5 h / 20 °C 3.1: piperidine / ethyl acetate / 1 h / 20 °C 3.2: 85 percent / SiO2 / ethyl acetate 4.1: 83 percent / NaOH; H2O / tetrahydrofuran / 2 h / 20 °C View Scheme

pyridine; Dess-Martin periodane in dichloromethane T=0 - 20°C; 5 h;