1.1: CDI / tetrahydrofuran / 3 h / 20 °C 1.2: 64 percent / n-BuLi / tetrahydrofuran; hexane / 4.5 h / -78 °C 2.1: 85 percent / CuCN / tetrahydrofuran / 3.5 h / 10 °C 3.1: TBAF / tetrahydrofuran / 5 h / 40 - 50 °C 3.2: 62 percent / benzene; CHCl3 / Heating 4.1: 65 percent / MgBr2*OEt2 / benzene; diethyl ether / 11 h / 0 - 20 °C View Scheme

1.1: CDI / tetrahydrofuran / 3 h / 20 °C 1.2: 64 percent / n-BuLi / tetrahydrofuran; hexane / 4.5 h / -78 °C 2.1: 85 percent / CuCN / tetrahydrofuran / 3.5 h / 10 °C 3.1: TBAF / tetrahydrofuran / 5 h / 40 - 50 °C 3.2: 62 percent / benzene; CHCl3 / Heating 4.1: 47 percent / LDA; Py*HCl / tetrahydrofuran / -78 - 20 °C 5.1: 81 percent / MgBr2*Et2O; EtSH / diethyl ether; benzene / 11 h / 0 - 20 °C View Scheme