1: 1.) BF3*OEt2 / 1.) THF, 0 deg C, 5 min, 2.) THF, 0 deg C, 1 h 2: Ph3P, NaH / tetrahydrofuran / 0.5 h / Ambient temperature View Scheme

1: 1.) BF3*OEt2 / 1.) THF, 0 deg C, 5 min, 2.) THF, 0 deg C, 1 h 2: Ph3P, NaH / tetrahydrofuran / 0.5 h / Ambient temperature View Scheme

1: 1.) BF3*OEt2 / 1.) THF, 0 deg C, 5 min, 2.) THF, 0 deg C, 6 h 2: 83 percent / Ph3P, NaH / tetrahydrofuran / 0.5 h / Ambient temperature View Scheme