1: 1.) n-BuLi / 1.) THF, hexane, from -78 deg C to RT, 20 min, 2.) hexane, THF, a) RT, overnight, b) 60 deg C, 1 h 2: 52 percent / SeO2 / aq. ethanol / 19 h / Heating 3: 1.) t-BuOK / 1.) t-BuOH, THF, 0 deg C, 15 min, 2.) t-BuOH, THF, a) 0 deg C, 2 h, b) RT, 18 h View Scheme

1: 52 percent / SeO2 / aq. ethanol / 19 h / Heating 2: 1.) t-BuOK / 1.) t-BuOH, THF, 0 deg C, 15 min, 2.) t-BuOH, THF, a) 0 deg C, 2 h, b) RT, 18 h View Scheme

sodium hydride in N,N-dimethyl-formamide 1.) RT, 16 h, 2.) 60 deg C, 45 min; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

potassium tert-butylate 1.) t-BuOH, THF, 0 deg C, 15 min, 2.) t-BuOH, THF, a) 0 deg C, 2 h, b) RT, 18 h; Yield given. Multistep reaction;