1.1: CuCN / tetrahydrofuran / 0.75 h / -78 °C 2.1: O3 / CH2Cl2; methanol / -116 °C 2.2: dimethyl sulfide / CH2Cl2; methanol / 2 h / -116 - 20 °C 3.1: diethyl ether / 0.25 h / 0 °C 4.1: 63 percent / KHMDS / tetrahydrofuran / 1.5 h / -78 °C 5.1: 96 percent / triethylsilane; LiCl / (PPh3)4Pd / dimethylformamide / 2 h / 55 °C 6.1: LiOH / tetrahydrofuran / 10 h / 0 - 20 °C 7.1: 0.0168 g / TFA / CH2Cl2 / 10 h View Scheme