1: 86 percent / acetonitrile / 24 h / Heating 2: 1) Natriumsilazid (NaHMDS) / 1) Et2O, a) -78 deg C, 4 h, b) -40 - -30 deg C, 0.5 h, 2) Et2O, -78 deg C to r.t., 12 h 4: 80 percent / Py / tetrahydrofuran / 1) -20 deg C, 0.5 h, 2) r.t., 3 h View Scheme