1: aq. NaOH / tetrahydrofuran 2: K2CO3 / acetone 3: SnCl4, HNO3 / CH2Cl2 / -20 °C 4: aq. NaOH / tetrahydrofuran View Scheme

in acetone

1.1: diethyl azodicarboxylate; Ph3P / tetrahydrofuran / 1 h / 0 °C 1.2: tetrahydrofuran / 20 °C 2.1: Cu(NO3)2*3H2O; acetic anhydride / 0 - 20 °C 3.1: 100 percent / aq. NaOH / tetrahydrofuran / 72 h View Scheme

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