1: DIBAL-H / tetrahydrofuran / 3 h / -78 °C 2: 80 percent / CCl4, PPh3 / 18 h / Heating 3: 92 percent / LiEt3BH / tetrahydrofuran / 1 h / -78 °C 4: 95 percent / CSA / methanol / 1 h / 25 °C 5: SO3*Py, DMSO, Et3N / tetrahydrofuran / 1 h / 0 °C 6: LDA / tetrahydrofuran / 1.) -78 to -40 deg C, 1 h, 2.) -78 deg C, 2 min 7: 2,6-lutidine / tetrahydrofuran / 1 h / -78 - 0 °C View Scheme

1: DIBAL-H / tetrahydrofuran / 3 h / -78 °C 2: 80 percent / CCl4, PPh3 / 18 h / Heating 3: 92 percent / LiEt3BH / tetrahydrofuran / 1 h / -78 °C 4: 95 percent / CSA / methanol / 1 h / 25 °C 5: SO3*Py, DMSO, Et3N / tetrahydrofuran / 1 h / 0 °C 6: LDA / tetrahydrofuran / 1.) -78 to -40 deg C, 1 h, 2.) -78 deg C, 2 min View Scheme