N-methyl-2-indolinone; tetrapropylammonium perruthennate in dichloromethane T=20°C;

1: 71 percent / DMAP / pyridine / 49 h / Ambient temperature 2: 99 percent / DBU / benzene / 0.5 h / Ambient temperature 3: 100 percent / LiAlH4 / tetrahydrofuran / 1 h / Ambient temperature 4: 98 percent / Et3N / CH2Cl2 / 0.67 h / 0 °C 5: 85 percent / Na, NH3 / tetrahydrofuran / 1.25 h / -78 °C 6: 72 percent / 4A molecular sieves, p-TSA / CH2Cl2 / 24 h / 20 °C 7: 99 percent / DIBAL / CH2Cl2; hexane / 5 h / Ambient temperature 8: 100 percent / NMO, TPAP / CH2Cl2 / 2 h / 20 °C View Scheme

1: 72 percent / p-TSA, 4 Angstroem molecular sieves / CH2Cl2 / 20 °C 2: 99 percent / diisobutylaluminum hydride / CH2Cl2 / 0 - 20 °C 3: 100 percent / TPAP, NMO / CH2Cl2 / 20 °C View Scheme

1: 85 percent / Na, NH3 / tetrahydrofuran / 1.25 h / -78 °C 2: 72 percent / 4A molecular sieves, p-TSA / CH2Cl2 / 24 h / 20 °C 3: 99 percent / DIBAL / CH2Cl2; hexane / 5 h / Ambient temperature 4: 100 percent / NMO, TPAP / CH2Cl2 / 2 h / 20 °C View Scheme