1: camphorsulfonic acid / Ambient temperature 2: H2 / Pd-C / ethanol / Ambient temperature 3: DMSO, (COCl)2, Et3N 4: NaH / dimethylformamide; tetrahydrofuran / 0 °C 5: H2 / Pd-C / ethyl acetate / Ambient temperature 6: tetrahydrofuran / -78 °C 7: 1.) O3, 2.) NaBH4 / 1.) CH2Cl2, -78 deg C 8: Et3N / 0 °C 9: 1N-HCl / tetrahydrofuran / Ambient temperature 10: K2CO3 / methanol 11: NaH / tetrahydrofuran / Ambient temperature 12: camphorsulfonic acid / CH2Cl2 / 0 °C 13: DMSO, (COCl)2, Et3N / CH2Cl2 14: 28 percent / (Ph3P)3RhCl / acetonitrile / 160 °C 15: DDQ / CH2Cl2; H2O 16: DMSO, (COCl)2 / CH2Cl2 17: TsOH / benzene 18: H2 / Pd-C / ethyl acetate 19: CrO3, H2SO4 / acetone 20: 2N-HCl / tetrahydrofuran / Ambient temperature 21: (C6H11)2NMgBr / methanol / -55 °C 22: DDQ / CH2Cl2 / 1.5 h / Ambient temperature; buffer (pH 6.86) View Scheme