sodium tetrahydroborate; diphenyl diselenide in ethanol 0.5 h; Ambient temperature;

1.1: POCl3; Et3N / diethyl ether / 1.25 h / -5 - 20 °C 2.1: Et3N / diethyl ether / -20 - 20 °C 3.1: 83 percent / n-BuLi / tetrahydrofuran; hexane / 2 h / -50 - 20 °C 4.1: n-BuLi / tetrahydrofuran; hexane / 1 h / -50 °C 4.2: 100 percent / tetrahydrofuran; hexane / 1 h / -50 - 20 °C 5.1: 83 percent / aq. H2SO4 / benzene / 4 h / Heating View Scheme

1.1: POCl3; Et3N / diethyl ether / 1.25 h / -5 - 20 °C 2.1: Et3N / diethyl ether / -20 - 20 °C 3.1: 83 percent / n-BuLi / tetrahydrofuran; hexane / 2 h / -50 - 20 °C 4.1: n-BuLi / tetrahydrofuran; hexane / 1 h / -50 °C 4.2: 100 percent / H2O / tetrahydrofuran; hexane / -50 °C 5.1: 69 percent / aq. H2SO4 / benzene / 4 h / Heating View Scheme

1.1: POCl3; Et3N / diethyl ether / 1.25 h / -5 - 20 °C 2.1: Et3N / diethyl ether / -20 - 20 °C 3.1: 83 percent / n-BuLi / tetrahydrofuran; hexane / 2 h / -50 - 20 °C 4.1: n-BuLi / tetrahydrofuran; hexane / 1 h / -50 °C 4.2: 47 percent / tetrahydrofuran; hexane / 2 h / -50 °C 5.1: 27 percent Spectr. / aq. HCl / diethyl ether / 4 h / 20 °C View Scheme

hydrogen; Lindlar's catalyst in pentane

sodium hydroxide 48 h;

1.1: POCl3; Et3N / diethyl ether / 1.25 h / -5 - 20 °C 2.1: Et3N / diethyl ether / -20 - 20 °C 3.1: 83 percent / n-BuLi / tetrahydrofuran; hexane / 2 h / -50 - 20 °C 4.1: n-BuLi / tetrahydrofuran; hexane / 1 h / -50 °C 4.2: 96 percent / tetrahydrofuran; hexane / 1 h / -50 - 20 °C 5.1: 62 percent / aq. H2SO4 / benzene / 4 h / Heating View Scheme