1: 93 percent / n-Bu4NF / tetrahydrofuran / 5 h / Ambient temperature 2: 47 percent / triphenylphosphine, dipyridyl disulfide / xylene / Ambient temperature 3: 35 mg / acetic acid; tetrahydrofuran; H2O / 4 h / 50 °C 4: TiCl4 / CH2Cl2 / 0.25 h / 0 °C View Scheme

1: 98 percent / 0.13N LiOH / methanol; H2O / 18 h / 50 °C 2: 93 percent / n-Bu4NF / tetrahydrofuran / 5 h / Ambient temperature 3: 47 percent / triphenylphosphine, dipyridyl disulfide / xylene / Ambient temperature 4: 35 mg / acetic acid; tetrahydrofuran; H2O / 4 h / 50 °C 5: TiCl4 / CH2Cl2 / 0.25 h / 0 °C View Scheme

1: 82 percent / n-BuLi / hexamethylphosphoric acid triamide; tetrahydrofuran; hexane / 1 h / Ambient temperature 2: 79 percent / Na / tetrahydrofuran; liquid ammonia / 1 h 3: 431 mg / PCC, NaOAc / CH2Cl2 / 2.5 h / Ambient temperature 4: 570 mg / diisopropylamine / dimethylsulfoxide / Ambient temperature 5: 54 percent / pyrrolidine / hexamethylphosphoric acid triamide / Ambient temperature 6: 97 percent / PPTS / CH2Cl2 / Ambient temperature 7: 98 percent / 0.13N LiOH / methanol; H2O / 18 h / 50 °C 8: 93 percent / n-Bu4NF / tetrahydrofuran / 5 h / Ambient temperature 9: 47 percent / triphenylphosphine, dipyridyl disulfide / xylene / Ambient temperature 10: 35 mg / acetic acid; tetrahydrofuran; H2O / 4 h / 50 °C 11: TiCl4 / CH2Cl2 / 0.25 h / 0 °C View Scheme

1: 89 percent / PPTS / CH2Cl2 / 18 h / Ambient temperature 2: diisobutylalane / toluene; hexane / 0.08 h / -75 °C 3: 52 percent / 1,2-dimethoxy-ethane / 0.08 h / -10 °C 4: 98 percent / i-Pr2NEt / CH2Cl2 / Ambient temperature 5: 94 percent / 75percent AcOH / 0.5 h / 35 °C 6: 83 percent / pyridine / 8 h / 0 °C 8: 1.15 mg / LiAlH4 / diethyl ether / 60 h / 0 °C 9: 96 percent / NaH / dimethylformamide / Ambient temperature 10: 1.43 g / pyridinum bromide perbromide / CHCl3 / 0.67 h / 0 °C 11: 81 percent / NaNH2, Fe(NO3)3 / tetrahydrofuran / 0.5 h 12: 82 percent / n-BuLi / hexamethylphosphoric acid triamide; tetrahydrofuran; hexane / 1 h / Ambient temperature 13: 79 percent / Na / tetrahydrofuran; liquid ammonia / 1 h 14: 431 mg / PCC, NaOAc / CH2Cl2 / 2.5 h / Ambient temperature 15: 570 mg / diisopropylamine / dimethylsulfoxide / Ambient temperature 16: 54 percent / pyrrolidine / hexamethylphosphoric acid triamide / Ambient temperature 17: 97 percent / PPTS / CH2Cl2 / Ambient temperature 18: 98 percent / 0.13N LiOH / methanol; H2O / 18 h / 50 °C 19: 93 percent / n-Bu4NF / tetrahydrofuran / 5 h / Ambient temperature 20: 47 percent / triphenylphosphine, dipyridyl disulfide / xylene / Ambient temperature 21: 35 mg / acetic acid; tetrahydrofuran; H2O / 4 h / 50 °C 22: TiCl4 / CH2Cl2 / 0.25 h / 0 °C View Scheme

1: 91 percent / NaBH4 / methanol / 1.5 h / -75 °C 2: TiCl4 / CH2Cl2 / 0.25 h / 0 °C View Scheme

1: 1.) dimethyl sulfoxide (1.1 equiv), (CF3CO)2O / 1.) CH2Cl2, -65 deg C, 2.) Et3N, 25 deg C, 1 h 2: K2CO3 / dimethylformamide / 48 h / 23 °C 3: 1.) CpZrHCl, 2.) Ni(acac)2, diisobutylaluminium hydride / 1.) THF, 0 deg C, 2.) THF, -10 deg C then 0 deg C, 8 h 4: 1.) Li-sec-Bu3BH (L-Selectride), 2.) tosic acid / 1.) THF, -78 deg C, 2 h, 2.) toluene, reflux, 10 h 5: 97 percent / diisopropylethylamine / CH2Cl2 / 10 h / 23 °C 6: 98 percent / i-Bu2AlH / CH2Cl2 / 1.5 h / -78 °C 7: 94 percent / piperidine / acetonitrile / 48 h / 5 °C 8: 90 percent / diisopropylethylamine / CH2Cl2 / 23 °C 9: 87 percent / HOAc, H2O (3:1) / 5 h / 23 °C 10: 93 percent / 0.15 M LiOH / 24 h / 23 °C / MeOH, H2O (6:1) 11: 1.) lactonization, 2.) MEM ether cleavage View Scheme

1: 1.) CpZrHCl, 2.) Ni(acac)2, diisobutylaluminium hydride / 1.) THF, 0 deg C, 2.) THF, -10 deg C then 0 deg C, 8 h 2: 1.) Li-sec-Bu3BH (L-Selectride), 2.) tosic acid / 1.) THF, -78 deg C, 2 h, 2.) toluene, reflux, 10 h 3: 97 percent / diisopropylethylamine / CH2Cl2 / 10 h / 23 °C 4: 98 percent / i-Bu2AlH / CH2Cl2 / 1.5 h / -78 °C 5: 94 percent / piperidine / acetonitrile / 48 h / 5 °C 6: 90 percent / diisopropylethylamine / CH2Cl2 / 23 °C 7: 87 percent / HOAc, H2O (3:1) / 5 h / 23 °C 8: 93 percent / 0.15 M LiOH / 24 h / 23 °C / MeOH, H2O (6:1) 9: 1.) lactonization, 2.) MEM ether cleavage View Scheme

1: K2CO3 / dimethylformamide / 48 h / 23 °C 2: 1.) CpZrHCl, 2.) Ni(acac)2, diisobutylaluminium hydride / 1.) THF, 0 deg C, 2.) THF, -10 deg C then 0 deg C, 8 h 3: 1.) Li-sec-Bu3BH (L-Selectride), 2.) tosic acid / 1.) THF, -78 deg C, 2 h, 2.) toluene, reflux, 10 h 4: 97 percent / diisopropylethylamine / CH2Cl2 / 10 h / 23 °C 5: 98 percent / i-Bu2AlH / CH2Cl2 / 1.5 h / -78 °C 6: 94 percent / piperidine / acetonitrile / 48 h / 5 °C 7: 90 percent / diisopropylethylamine / CH2Cl2 / 23 °C 8: 87 percent / HOAc, H2O (3:1) / 5 h / 23 °C 9: 93 percent / 0.15 M LiOH / 24 h / 23 °C / MeOH, H2O (6:1) 10: 1.) lactonization, 2.) MEM ether cleavage View Scheme

1: 1.) Li-sec-Bu3BH (L-Selectride), 2.) tosic acid / 1.) THF, -78 deg C, 2 h, 2.) toluene, reflux, 10 h 2: 97 percent / diisopropylethylamine / CH2Cl2 / 10 h / 23 °C 3: 98 percent / i-Bu2AlH / CH2Cl2 / 1.5 h / -78 °C 4: 94 percent / piperidine / acetonitrile / 48 h / 5 °C 5: 90 percent / diisopropylethylamine / CH2Cl2 / 23 °C 6: 87 percent / HOAc, H2O (3:1) / 5 h / 23 °C 7: 93 percent / 0.15 M LiOH / 24 h / 23 °C / MeOH, H2O (6:1) 8: 1.) lactonization, 2.) MEM ether cleavage View Scheme

1: 97 percent / diisopropylethylamine / CH2Cl2 / 10 h / 23 °C 2: 98 percent / i-Bu2AlH / CH2Cl2 / 1.5 h / -78 °C 3: 94 percent / piperidine / acetonitrile / 48 h / 5 °C 4: 90 percent / diisopropylethylamine / CH2Cl2 / 23 °C 5: 87 percent / HOAc, H2O (3:1) / 5 h / 23 °C 6: 93 percent / 0.15 M LiOH / 24 h / 23 °C / MeOH, H2O (6:1) 7: 1.) lactonization, 2.) MEM ether cleavage View Scheme