1.1: 86 percent / MnO2 / toluene / 1 h / 20 °C 2.1: 95 percent / NBS / dimethylformamide / 0.5 h / 0 °C 3.1: t-BuLi / tetrahydrofuran; pentane / 0.5 h / -78 °C 3.2: 89 percent / tetrahydrofuran; pentane / 1.5 h / -78 - 0 °C View Scheme

trifluoroacetic acid in toluene T=150°C; aza-Claisen rearrangement; 0.166667 h; microwave irradiation;