lithium borohydride; ethanol in tetrahydrofuran 1 h; Inert atmosphere;

pyrrolidine; tetrakis(triphenylphosphine) palladium(0); triphenylphosphine in dichloromethane; acetonitrile T=20°C; 2.25 h;

1: oxalyl chloride; DMF / tetrahydrofuran / 16 h 2: Et3N / tetrahydrofuran; H2O / 2 h / 20 °C 3: 94 percent / TBAF / tetrahydrofuran / 0.5 h / 0 - 20 °C 4: 61 percent / SnCl2*2H2O / methanol / 0.75 h / Heating 5: 50 percent / pyridine / CH2Cl2 / 2.5 h / 20 °C 6: 32 percent / NMO; 4 Angstroem molecular sieves; TPAP / CH2Cl2; acetonitrile / 2.5 h / 20 °C 7: 77 percent / PPh3; pyrrolidine; Pd(PPh3)4 / CH2Cl2; acetonitrile / 2.25 h / 20 °C View Scheme

1: 43 percent / H2SO4 / 2 h / Heating 2: 99 percent / LiBH4 / tetrahydrofuran / 2.5 h / 0 - 20 °C 3: 52 percent / Et3N; DBU / CH2Cl2 / 16 h / 20 °C 4: 95 percent / oxalyl chloride; DMSO; Et3N / CH2Cl2 / 1.5 h / -70 °C 5: 87 percent / tetrahydrofuran / 2 h / 0 °C 6: 77 percent / PdCl2(PPh3)2; Bu3SnH / H2O; CH2Cl2 / 16 h / 20 °C 7: Et3N / tetrahydrofuran; H2O / 2 h / 20 °C 8: 94 percent / TBAF / tetrahydrofuran / 0.5 h / 0 - 20 °C 9: 61 percent / SnCl2*2H2O / methanol / 0.75 h / Heating 10: 50 percent / pyridine / CH2Cl2 / 2.5 h / 20 °C 11: 32 percent / NMO; 4 Angstroem molecular sieves; TPAP / CH2Cl2; acetonitrile / 2.5 h / 20 °C 12: 77 percent / PPh3; pyrrolidine; Pd(PPh3)4 / CH2Cl2; acetonitrile / 2.25 h / 20 °C View Scheme

1: 87 percent / 4 M NaOH / tetrahydrofuran; H2O / 1 h / 0 °C / pH 9 2: 43 percent / H2SO4 / 2 h / Heating 3: 99 percent / LiBH4 / tetrahydrofuran / 2.5 h / 0 - 20 °C 4: 52 percent / Et3N; DBU / CH2Cl2 / 16 h / 20 °C 5: 95 percent / oxalyl chloride; DMSO; Et3N / CH2Cl2 / 1.5 h / -70 °C 6: 87 percent / tetrahydrofuran / 2 h / 0 °C 7: 77 percent / PdCl2(PPh3)2; Bu3SnH / H2O; CH2Cl2 / 16 h / 20 °C 8: Et3N / tetrahydrofuran; H2O / 2 h / 20 °C 9: 94 percent / TBAF / tetrahydrofuran / 0.5 h / 0 - 20 °C 10: 61 percent / SnCl2*2H2O / methanol / 0.75 h / Heating 11: 50 percent / pyridine / CH2Cl2 / 2.5 h / 20 °C 12: 32 percent / NMO; 4 Angstroem molecular sieves; TPAP / CH2Cl2; acetonitrile / 2.5 h / 20 °C 13: 77 percent / PPh3; pyrrolidine; Pd(PPh3)4 / CH2Cl2; acetonitrile / 2.25 h / 20 °C View Scheme

1: 99 percent / LiBH4 / tetrahydrofuran / 2.5 h / 0 - 20 °C 2: 52 percent / Et3N; DBU / CH2Cl2 / 16 h / 20 °C 3: 95 percent / oxalyl chloride; DMSO; Et3N / CH2Cl2 / 1.5 h / -70 °C 4: 87 percent / tetrahydrofuran / 2 h / 0 °C 5: 77 percent / PdCl2(PPh3)2; Bu3SnH / H2O; CH2Cl2 / 16 h / 20 °C 6: Et3N / tetrahydrofuran; H2O / 2 h / 20 °C 7: 94 percent / TBAF / tetrahydrofuran / 0.5 h / 0 - 20 °C 8: 61 percent / SnCl2*2H2O / methanol / 0.75 h / Heating 9: 50 percent / pyridine / CH2Cl2 / 2.5 h / 20 °C 10: 32 percent / NMO; 4 Angstroem molecular sieves; TPAP / CH2Cl2; acetonitrile / 2.5 h / 20 °C 11: 77 percent / PPh3; pyrrolidine; Pd(PPh3)4 / CH2Cl2; acetonitrile / 2.25 h / 20 °C View Scheme

1: 52 percent / Et3N; DBU / CH2Cl2 / 16 h / 20 °C 2: 95 percent / oxalyl chloride; DMSO; Et3N / CH2Cl2 / 1.5 h / -70 °C 3: 87 percent / tetrahydrofuran / 2 h / 0 °C 4: 77 percent / PdCl2(PPh3)2; Bu3SnH / H2O; CH2Cl2 / 16 h / 20 °C 5: Et3N / tetrahydrofuran; H2O / 2 h / 20 °C 6: 94 percent / TBAF / tetrahydrofuran / 0.5 h / 0 - 20 °C 7: 61 percent / SnCl2*2H2O / methanol / 0.75 h / Heating 8: 50 percent / pyridine / CH2Cl2 / 2.5 h / 20 °C 9: 32 percent / NMO; 4 Angstroem molecular sieves; TPAP / CH2Cl2; acetonitrile / 2.5 h / 20 °C 10: 77 percent / PPh3; pyrrolidine; Pd(PPh3)4 / CH2Cl2; acetonitrile / 2.25 h / 20 °C View Scheme

1: Et3N / tetrahydrofuran; H2O / 2 h / 20 °C 2: 94 percent / TBAF / tetrahydrofuran / 0.5 h / 0 - 20 °C 3: 61 percent / SnCl2*2H2O / methanol / 0.75 h / Heating 4: 50 percent / pyridine / CH2Cl2 / 2.5 h / 20 °C 5: 32 percent / NMO; 4 Angstroem molecular sieves; TPAP / CH2Cl2; acetonitrile / 2.5 h / 20 °C 6: 77 percent / PPh3; pyrrolidine; Pd(PPh3)4 / CH2Cl2; acetonitrile / 2.25 h / 20 °C View Scheme

1: 87 percent / tetrahydrofuran / 2 h / 0 °C 2: 77 percent / PdCl2(PPh3)2; Bu3SnH / H2O; CH2Cl2 / 16 h / 20 °C 3: Et3N / tetrahydrofuran; H2O / 2 h / 20 °C 4: 94 percent / TBAF / tetrahydrofuran / 0.5 h / 0 - 20 °C 5: 61 percent / SnCl2*2H2O / methanol / 0.75 h / Heating 6: 50 percent / pyridine / CH2Cl2 / 2.5 h / 20 °C 7: 32 percent / NMO; 4 Angstroem molecular sieves; TPAP / CH2Cl2; acetonitrile / 2.5 h / 20 °C 8: 77 percent / PPh3; pyrrolidine; Pd(PPh3)4 / CH2Cl2; acetonitrile / 2.25 h / 20 °C View Scheme

1: 95 percent / oxalyl chloride; DMSO; Et3N / CH2Cl2 / 1.5 h / -70 °C 2: 87 percent / tetrahydrofuran / 2 h / 0 °C 3: 77 percent / PdCl2(PPh3)2; Bu3SnH / H2O; CH2Cl2 / 16 h / 20 °C 4: Et3N / tetrahydrofuran; H2O / 2 h / 20 °C 5: 94 percent / TBAF / tetrahydrofuran / 0.5 h / 0 - 20 °C 6: 61 percent / SnCl2*2H2O / methanol / 0.75 h / Heating 7: 50 percent / pyridine / CH2Cl2 / 2.5 h / 20 °C 8: 32 percent / NMO; 4 Angstroem molecular sieves; TPAP / CH2Cl2; acetonitrile / 2.5 h / 20 °C 9: 77 percent / PPh3; pyrrolidine; Pd(PPh3)4 / CH2Cl2; acetonitrile / 2.25 h / 20 °C View Scheme