1: 92 percent / PPh3, CBr4 / CH2Cl2 / -40 - 0 °C 2: 81 percent / aq. AcOH / tetrahydrofuran / 45 °C 3: 75 percent / CrO3/pyridine / CH2Cl2 / 0 °C 4: LDA / tetrahydrofuran / -78 deg C, 8 h; -20 deg C, 1 h; room temp., 1 h 5: 60 percent / H2 / Lindlar catalyst / CH2Cl2 / 22 h / Ambient temperature 6: 73 percent / n-Bu4NF / tetrahydrofuran / 5 h / Ambient temperature View Scheme