1: With benzoic acid in chloroform T=-50°C; aza-Michael addition; 22 h; 2: With sodium tetrahydroborate in methanol; chloroform T=0°C; 0.5 h; Further stages. Title compound not separated from byproducts.;

Hoveyda-Grubbs catalyst second generation in dichloromethane T=20°C; 7 h;

manganese(IV) oxide in dichloromethane T=23°C; 12 h;

1: 99 percent / 4-(dimethylamino)pyridine / acetonitrile / 2 h / 23 °C 2: 100 percent / DIBALH / tetrahydrofuran / 1 h / -78 °C 3: 99 percent / toluene / 13 h / 100 °C 4: 76 percent / DIBALH / CH2Cl2 / 3 h / -78 °C 5: 92 percent / MnO2 / CH2Cl2 / 12 h / 23 °C View Scheme

1: 99 percent / toluene / 13 h / 100 °C 2: 76 percent / DIBALH / CH2Cl2 / 3 h / -78 °C 3: 92 percent / MnO2 / CH2Cl2 / 12 h / 23 °C View Scheme

1: 100 percent / DIBALH / tetrahydrofuran / 1 h / -78 °C 2: 99 percent / toluene / 13 h / 100 °C 3: 76 percent / DIBALH / CH2Cl2 / 3 h / -78 °C 4: 92 percent / MnO2 / CH2Cl2 / 12 h / 23 °C View Scheme

1: 76 percent / DIBALH / CH2Cl2 / 3 h / -78 °C 2: 92 percent / MnO2 / CH2Cl2 / 12 h / 23 °C View Scheme