1: LDA, DMPU / tetrahydrofuran / 1.) -78 deg C, 10 min, 2.) -78 deg C, 5 h 2: AcOH, NaOAc, H2O / diethyl ether / 1 h 3: 100 percent / Et3N / benzene / 0.5 h / 0 °C 4: Me3Al/AlCl3 / benzene; tetrahydrofuran; toluene / 2 h / Ambient temperature 5: H2O, SiO2 6: 55 percent / benzene / 0 °C / Irradiation 7: TFA / CH2Cl2 / 1 h / 0 °C View Scheme

With  carbon tetrabromide; triphenylphosphine in  acetonitrile 12 h;  Ambient temperature;   

Multi-step reaction with 2 steps 1: LDA, DMPU / tetrahydrofuran / 1.) -78 deg C, 10 min, 2.) -78 deg C, 5 h2: AcOH, NaOAc, H2O / diethyl ether / 1 h  

Multi-step reaction with 2 steps 1: lithium diisopropyl amide, N,N'-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone / tetrahydrofuran / -78 - -60 °C2: Et3N / benzene  

Multi-step reaction with 7 steps 1: 85 percent / Mg, dibromoethane, EtMgBr / diethyl ether / 8 h / Heating2: 98 percent / DMAP, imidazole / CH2Cl2 / 4 h / Ambient temperature3: tetra-n-butylammonium chloride, ethyl chloroformate, K2CO3 / tetrahydrofuran / 0.33 h / Ambient temperature4: n-butyllithium / tetrahydrofuran; various solvent(s) / 12 h / -80 °C5: HgCl2, CaCO3 / acetonitrile; H2O / 4 h / Heating6: NaBH4 / ethanol / 2 h / Ambient temperature7: 42 percent / tetra-n-propylammmonium perruthenate, crushed 4 Angstroem molecular sieves, N-methylmorpholine N-oxide / CH2Cl2; acetonitrile / 3 h / Ambient temperature