1: boron trifluoride diethyl etherate / 75 °C / Inert atmosphere 2: pyridine; 4-(N,N-dimethlyamino)pyridine / 1 h / 150 °C / Inert atmosphere; Microwave irradiation 3: tetrabutyl ammonium fluoride / tetrahydrofuran / 0.5 h / 20 °C / Inert atmosphere 4: hydrazine / ethanol / 10 h / 68 °C / Inert atmosphere View Scheme

With  di-isopropyl azodicarboxylate; triphenylphosphine in  tetrahydrofuran T=40°C;   

Multi-step reaction with 2 steps 1.1: potassium hexamethylsilazane / tetrahydrofuran / 6 h / -78 °C / Inert atmosphere1.2: -78 - 20 °C / Inert atmosphere2.1: sodium hydrogencarbonate; 3-chloro-benzenecarboperoxoic acid / toluene / 2 h / 0 °C / Inert atmosphere2.2: 5 h / 60 °C / Inert atmosphere2.3: 20 °C / Inert atmosphere; Molecular sieve  

With  copper(II) bis(trifluoromethanesulfonate) in  methylbutan-2-ol T=0 - 100°C;  Inert atmosphere;