1.1: i-PrMgBr / tetrahydrofuran / 1 h / 0 °C 1.2: ZnCl2 / tetrahydrofuran; diethyl ether / 1 h / 20 °C 1.3: Pd(PPh3)4 / dimethylformamide; tetrahydrofuran; diethyl ether / 1 h / 80 °C 2.1: 0.70 g / benzenesulfonic acid / toluene / 2 h / Heating 3.1: n-BuLi / tetrahydrofuran; hexane / 0.08 h / -78 °C 3.2: 4-toluenesulfonyl azide / tetrahydrofuran; hexane / 5 h / -78 °C 3.3: tetrasodium pyrophosphate decahydrate / tetrahydrofuran; hexane; H2O / 20 °C 4.1: aq. HCl / diethyl ether; tetrahydrofuran; hexane / 3 h / 20 °C 5.1: 140 mg / tributylphosphine / toluene; tetrahydrofuran / 2 h / 20 °C View Scheme

1.1: i-PrMgBr / tetrahydrofuran / 1 h / 0 °C 1.2: ZnCl2 / tetrahydrofuran; diethyl ether / 1 h / 20 °C 1.3: Pd(PPh3)4 / dimethylformamide; tetrahydrofuran; diethyl ether / 1 h / 80 °C 2.1: 0.70 g / benzenesulfonic acid / toluene / 2 h / Heating 3.1: n-BuLi / tetrahydrofuran; hexane / 0.08 h / -78 °C 3.2: 4-toluenesulfonyl azide / tetrahydrofuran; hexane / 5 h / -78 °C 3.3: tetrasodium pyrophosphate decahydrate / tetrahydrofuran; hexane; H2O / 20 °C 4.1: aq. HCl / diethyl ether; tetrahydrofuran; hexane / 3 h / 20 °C 5.1: 140 mg / tributylphosphine / toluene; tetrahydrofuran / 2 h / 20 °C View Scheme

1.1: n-BuLi / tetrahydrofuran; hexane / 0.08 h / -78 °C 1.2: 4-toluenesulfonyl azide / tetrahydrofuran; hexane / 5 h / -78 °C 1.3: tetrasodium pyrophosphate decahydrate / tetrahydrofuran; hexane; H2O / 20 °C 2.1: aq. HCl / diethyl ether; tetrahydrofuran; hexane / 3 h / 20 °C 3.1: 140 mg / tributylphosphine / toluene; tetrahydrofuran / 2 h / 20 °C View Scheme