1: 1.) LDA, 2.) HMPA / 1.) THF, hexane, -78 deg C, 45 min, 2.) THF, hexane, room temperature, 30 min 2: 1.) LiAlH4, 2.) 25percent H2SO4 / 1.) ether, 0 deg C, 2.) ether, water, 0 deg C, 30 min View Scheme

1: 70 percent / LDA / tetrahydrofuran / -78 - 20 °C 2: 97 percent / 2N HCl / tetrahydrofuran / 1 h / Ambient temperature 3: 84 percent / oxalyl chloride / CHCl3 / room temp., 30 min., then reflux 40 min. 4: 80 percent / Zn-Ag / methanol / 0.58 h / Ambient temperature View Scheme