1: 88.2 percent / DIBAL / toluene; tetrahydrofuran / 1 h / -78 °C 2: (n-Bu)4NF / tetrahydrofuran / 2 h / Ambient temperature View Scheme

1: 88.2 percent / DIBAL / toluene; tetrahydrofuran / 1 h / -78 °C 2: 86.9 percent / POCl3 / 3 h / Ambient temperature 3: 84 percent / BF3*Et2O / acetonitrile / 1 h / Ambient temperature View Scheme