1: aq. KOH / ethanol / 2 h / Heating 2: 3.56 g / K2CO3 / acetone / 2.5 h / Heating 3: 96 percent / oxalic acid dihydrate / aq. methanol / 2.5 h / Heating View Scheme

1.1: aq. KOH / ethanol / 2 h / Heating 2.1: 3.56 g / K2CO3 / acetone / 2.5 h / Heating 3.1: 96 percent / oxalic acid dihydrate / aq. methanol / 2.5 h / Heating 4.1: 90 percent / K2CO3 / acetone / 2 h / Heating 5.1: 94 percent / KI; CuI / hexamethylphosphoric acid triamide / 3 h / 150 °C 6.1: 96 percent / CuI; i-Pr2NH / PdCl2(PPh3)2 / dimethylformamide / 1.5 h / 60 °C 7.1: 71 percent / K2CO3; CuCl2*2H2O; NaOAc / PdCl2(PPh3)2 / 48 h / 20 °C 8.1: 72 percent / BBr3 / CH2Cl2 / 30.5 h / -78 - -40 °C 9.1: KOH / tetrahydrofuran / 2 h / Heating 9.2: 53 percent / TsOH*H2O / tetrahydrofuran / 5 h / 60 °C View Scheme

1: aq. KOH / ethanol / 2 h / Heating 2: 3.56 g / K2CO3 / acetone / 2.5 h / Heating 3: 96 percent / oxalic acid dihydrate / aq. methanol / 2.5 h / Heating 4: 90 percent / K2CO3 / acetone / 2 h / Heating 5: 94 percent / KI; CuI / hexamethylphosphoric acid triamide / 3 h / 150 °C 6: 96 percent / CuI; i-Pr2NH / PdCl2(PPh3)2 / dimethylformamide / 1.5 h / 60 °C 7: 81 percent / DIBAL-H / toluene; CH2Cl2 / 3 h / -78 °C 8: 67 percent / TBAF / tetrahydrofuran / 3 h / Heating 9: 78 percent / NaOMe / methanol / 20 h / Heating View Scheme