1: TBAF / tetrahydrofuran / 0.5 h 2: TsOH / 0.25 h 3: 1.) catecholborane, 2.) H2O2, NaOH / 1.) (PPh3)3RhCl / 1.) THF, 45 min 4: 1.) (COCl)2, DMSO, 2.) Et3N 5: NaH / tetrahydrofuran / 4 h 6: H2 / 10percent Pd/C / ethanol; ethyl acetate / 5 h 7: tetrahydrofuran / 3 h 8: HCl, H2O / tetrahydrofuran / 3 h / 50 °C 9: 90 percent / TsOH / benzene / 0.5 h 10: 94 percent / 2,6-lutidine / CH2Cl2 / 4 h / -78 °C 11: 75 percent / DIBAL-H / CH2Cl2 / 1.5 h / -78 - -15 °C 12: 1.) (COCl)2, DMSO, 2.) Et3N 14: 2,6-lutidine / CH2Cl2 / 4 h / -50 °C 15: DDQ, H2O / CH2Cl2 / 3 h / 0 °C 16: Dess-Martin periodinane 17: Mo(CHMe2Ph)<N(2,6-(i-Pr)2C6H3)><OCMe(CF3)2>2 / benzene / 4 h / 55 °C 18: 60 percent / HF*pyridine / tetrahydrofuran / 3 h 19: 86 percent / dimethyldioxirane / CH2Cl2 / 4 h / -50 °C View Scheme

1: TBAF / tetrahydrofuran / 0.5 h 2: TsOH / 0.25 h 3: 1.) catecholborane, 2.) H2O2, NaOH / 1.) (PPh3)3RhCl / 1.) THF, 45 min 4: 1.) (COCl)2, DMSO, 2.) Et3N 5: NaH / tetrahydrofuran / 4 h 6: H2 / 10percent Pd/C / ethanol; ethyl acetate / 5 h 7: tetrahydrofuran / 3 h 8: HCl, H2O / tetrahydrofuran / 3 h / 50 °C 9: 90 percent / TsOH / benzene / 0.5 h 10: 94 percent / 2,6-lutidine / CH2Cl2 / 4 h / -78 °C 11: 75 percent / DIBAL-H / CH2Cl2 / 1.5 h / -78 - -15 °C 12: 1.) (COCl)2, DMSO, 2.) Et3N 14: 2,6-lutidine / CH2Cl2 / 4 h / -50 °C 15: DDQ, H2O / CH2Cl2 / 3 h / 0 °C 16: Dess-Martin periodinane 17: Mo(CHMe2Ph)<N(2,6-(i-Pr)2C6H3)><OCMe(CF3)2>2 / benzene / 4 h / 55 °C 18: 60 percent / HF*pyridine / tetrahydrofuran / 3 h View Scheme