1: 2 h / 100 °C 2: KHMDS / tetrahydrofuran / 1.) 0 deg C, 30 min, 2.) -78 deg C, 3 h 3: benzene / 18 h / Heating 4: DIBAL-H / tetrahydrofuran / 3 h / -78 °C 5: 80 percent / CCl4, PPh3 / 18 h / Heating 6: 92 percent / LiEt3BH / tetrahydrofuran / 1 h / -78 °C 7: 95 percent / CSA / methanol / 1 h / 25 °C 8: SO3*Py, DMSO, Et3N / tetrahydrofuran / 1 h / 0 °C 9: LDA / tetrahydrofuran / 1.) -78 to -40 deg C, 1 h, 2.) -78 deg C, 2 min 10: 2,6-lutidine / tetrahydrofuran / 1 h / -78 - 0 °C View Scheme

1: 2 h / 100 °C 2: KHMDS / tetrahydrofuran / 1.) 0 deg C, 30 min, 2.) -78 deg C, 3 h 3: benzene / 18 h / Heating 4: DIBAL-H / tetrahydrofuran / 3 h / -78 °C 5: 80 percent / CCl4, PPh3 / 18 h / Heating 6: 92 percent / LiEt3BH / tetrahydrofuran / 1 h / -78 °C 7: 95 percent / CSA / methanol / 1 h / 25 °C 8: SO3*Py, DMSO, Et3N / tetrahydrofuran / 1 h / 0 °C 9: LDA / tetrahydrofuran / 1.) -78 to -40 deg C, 1 h, 2.) -78 deg C, 2 min View Scheme

1: 92 percent / 2 h / 100 °C 2: 1.) NaHMDS / 1.) THF, 0 deg C, 0.25 h, 2.) 0 deg C, 15 min 3: 86 percent / CSA / CH2Cl2; methanol / 1.) 0 deg C, 1 h, 2.) 25 deg C, 0.5 h 4: 82 percent / SO3*pyridine, DMSO, Et3N / CH2Cl2 / 0.5 h / 25 °C 5: LDA / tetrahydrofuran / 1.) -78 to -40 deg C, 0.5 h, 2.) -78 deg C 6: 2,6-lutidine / CH2Cl2 / 2 h / 0 °C 7: K2CO3 / methanol / 0.25 h / 25 °C 8: 79 percent / TBAF / tetrahydrofuran / 8 h / 25 °C 9: 1.) 2,4,6-trichlorobenzoylchloride, Et3N, 2.) 4-DMAP / 1.) THF, 25 deg C, 15 min, 2.) toluene, 25 deg C, 0.5 h 10: 92 percent / CF3COOH / CH2Cl2 / 1 h / 0 °C View Scheme