1: 95 percent / NaN3 / dimethylsulfoxide / 24 h / 45 - 50 °C 2: 1.) LDA / 1.) THF, -80 deg C, 15 min, 2.) -80 deg C, 30 min then -80 deg C to -20 deg C, 2h View Scheme

lithium diisopropyl amide 1.) THF, -80 deg C, 15 min, 2.) -80 deg C, 30 min then -80 deg C to -20 deg C, 2h; Yield given. Multistep reaction;

water; triphenylphosphine in tetrahydrofuran 12 h; Ambient temperature;