1: 1.) tosyl chloride, pyridine 2.) lithium bromide, acetone 2: lithium diisopropyl amide, N,N'-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone / tetrahydrofuran / -78 - -60 °C 3: Et3N / benzene 4: 52 percent / BF3*OEt2 / CH2Cl2 / -55 °C 5: 1.) irradiation at 300 nm, benzene 2.) 1O2, CH3OH View Scheme

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

Multi-step reaction with 2 steps 1: 1.) tosyl chloride, pyridine 2.) lithium bromide, acetone2: lithium diisopropyl amide, N,N'-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone / tetrahydrofuran / -78 - -60 °C  

Multi-step reaction with 3 steps 1: 1.) tosyl chloride, pyridine 2.) lithium bromide, acetone2: lithium diisopropyl amide, N,N'-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone / tetrahydrofuran / -78 - -60 °C3: Et3N / benzene  

Multi-step reaction with 9 steps 1: triethylamine / CH2Cl2 / 0.67 h / -10 °C2: LiBr / acetone / 3 h / Heating3: 85 percent / Mg, dibromoethane, EtMgBr / diethyl ether / 8 h / Heating4: 98 percent / DMAP, imidazole / CH2Cl2 / 4 h / Ambient temperature5: tetra-n-butylammonium chloride, ethyl chloroformate, K2CO3 / tetrahydrofuran / 0.33 h / Ambient temperature6: n-butyllithium / tetrahydrofuran; various solvent(s) / 12 h / -80 °C7: HgCl2, CaCO3 / acetonitrile; H2O / 4 h / Heating8: NaBH4 / ethanol / 2 h / Ambient temperature9: 42 percent / tetra-n-propylammmonium perruthenate, crushed 4 Angstroem molecular sieves, N-methylmorpholine N-oxide / CH2Cl2; acetonitrile / 3 h / Ambient temperature