1: 1.) Tf2O, N,N-diisopropylethylamine, 2.) aq. NaHCO3 / 1.) CH2Cl2, -78 deg C, 3 h, 2.) CH2Cl2, from -78 deg C to RT 2: PhI(OAc)2, I2 / cyclohexane / 1.5 h / Irradiation 3: 1.) Bu3SnH, AIBN, 2.) DBU, I2 / 1.) THF, reflux, 40 min, 2.) THF, ether View Scheme

trifluoromethylsulfonic anhydride; N-ethyl-N,N-diisopropylamine in toluene 1.) -78 deg C, 5 h, 2.) from -78 deg C to 0 deg C, 3.) 12 h, RT; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

1: N,N-diisopropylethylamine, Tf2O / CH2Cl2 / 1.) -78 deg C, 5 h, 2.) from -78 deg C to 0 deg C, 3.) 12 h, RT 2: 1.) N,N-diisopropylethylamine, Tf2O, 2.) O3, 3.) Me2S View Scheme

dimethylsulfide; trifluoromethylsulfonic anhydride; ozone; N-ethyl-N,N-diisopropylamine Yield given. Multistep reaction;