1.1: BuLi; HMPA / hexane; tetrahydrofuran / 0.5 h / 0 °C 1.2: 89.4 percent / hexane; tetrahydrofuran / 1 h / 0 °C 2.1: 77.3 percent / hydroquinone; aq. H3PO4 / dioxane / 4.5 h / 100 °C 3.1: 60.8 percent / methanol / 1.5 h / 20 °C 4.1: 79.5 percent / Ag2O / CH2Cl2 / 24 h / 20 °C 5.1: 95.4 percent / NaI / acetone / 24 h / Heating 6.1: 82.4 percent / NaHCO3; DMSO / 11 h / 90 °C 7.1: BuLi / hexane; tetrahydrofuran / 1 h / 20 °C 7.2: 69.3 percent / tetrahydrofuran / 0.5 h / 20 °C 8.1: 75 percent / BBr3 / CH2Cl2 / 1 h / 20 °C 9.1: 88.5 percent / 10 percent NaOH / ethanol / 6 h / Heating View Scheme

1: Na, liq. NH3 / diethyl ether 2: NaNH2 / diethyl ether 3: H2 / Lindlar catalyst / methanol 4: NaI / dimethylsulfoxide View Scheme

1.1: BuLi; HMPA / hexane; tetrahydrofuran / 0.5 h / 0 °C 1.2: 89.4 percent / hexane; tetrahydrofuran / 1 h / 0 °C 2.1: 77.3 percent / hydroquinone; aq. H3PO4 / dioxane / 4.5 h / 100 °C 3.1: 60.8 percent / methanol / 1.5 h / 20 °C 4.1: 79.5 percent / Ag2O / CH2Cl2 / 24 h / 20 °C 5.1: 95.4 percent / NaI / acetone / 24 h / Heating 6.1: 82.4 percent / NaHCO3; DMSO / 11 h / 90 °C 7.1: BuLi / tetrahydrofuran / 1 h / 20 °C 7.2: 76.4 percent / tetrahydrofuran / 0.5 h / 0 °C 8.1: 66.9 percent / BBr3 / CH2Cl2 / 0.25 h / 20 °C 9.1: 92.9 percent / 10 percent NaOH / ethanol / 2 h / Heating View Scheme

1.1: BuLi; HMPA / hexane; tetrahydrofuran / 0.5 h / 0 °C 1.2: 89.4 percent / hexane; tetrahydrofuran / 1 h / 0 °C 2.1: 77.3 percent / hydroquinone; aq. H3PO4 / dioxane / 4.5 h / 100 °C 3.1: 60.8 percent / methanol / 1.5 h / 20 °C 4.1: 79.5 percent / Ag2O / CH2Cl2 / 24 h / 20 °C 5.1: 95.4 percent / NaI / acetone / 24 h / Heating 6.1: 82.4 percent / NaHCO3; DMSO / 11 h / 90 °C 7.1: BuLi / hexane; tetrahydrofuran / 1 h / 20 °C 7.2: 66.7 percent / tetrahydrofuran / 0.5 h / 20 °C 8.1: 97.1 percent / BBr3 / CH2Cl2 / 1 h / 20 °C 9.1: 86.5 percent / 10 percent NaOH / ethanol / 6 h / Heating View Scheme

1: Na, liq. NH3 / diethyl ether 2: NaNH2 / diethyl ether 3: H2 / Lindlar catalyst / methanol View Scheme