1: 66 percent / Li2CuCl4 / tetrahydrofuran / 12 h / 20 °C 2: 98 percent / LDA / tetrahydrofuran; hexamethylphosphoric acid triamide / -78 - -50 °C 3: 92 percent / p-TsOH / methanol / 16 h / 20 °C 4: 88 percent / Na(Hg); Na2HPO4 / methanol / 21 h / 20 °C 5: 91 percent / LiAlH4 / tetrahydrofuran / Heating View Scheme

1.1: 66 percent / Li2CuCl4 / tetrahydrofuran / 12 h / 20 °C 2.1: CuI / 16 h / 60 °C 2.2: Me2Cu(CN)(MgCl)2; DMPU / tetrahydrofuran / -78 - 0 °C View Scheme