1: potassium t-butoxide / tetrahydrofuran / 1 h / -78 °C 2: N-iodosuccinimide / 1 h / -20 °C 3: SnCl4 / 1,2-dichloro-ethane / -20 deg C -> 23 deg C 4: H2 / 10 percent Pd/C / ethanol / 3 h 5: CH3ONa / methanol / 5 h / 23 °C View Scheme

1: potassium t-butoxide / tetrahydrofuran / 1 h / -78 °C 2: N-iodosuccinimide / tetrahydrofuran / 2 h / -15 °C 3: DBU / CH2Cl2 / 1 h / 0 °C 4: 82 percent / potassium t-butoxide / tetrahydrofuran / 1 h / 0 °C 5: 95 percent / sodium methoxide / methanol / 4 h / 23 °C View Scheme

1: potassium t-butoxide / tetrahydrofuran / 1 h / -78 °C 2: N-iodosuccinimide / tetrahydrofuran / 2 h / -15 °C 3: DBU / CH2Cl2 / 1 h / 0 °C 4: 82 percent / potassium t-butoxide / tetrahydrofuran / 1 h / 0 °C View Scheme