1: 70 percent / Dowex 50W X-8 / methanol / 3 h / Ambient temperature 2: 95 percent / hydrogen / 10percent Pd-C / methanol / 4 h / 760 Torr 3: 1.) dimethyl sulphoxide, oxalyl chloride, 2.) triethylamine / 1.) CH2Cl2, -60 deg C, 10 min, 2.) -60 deg C, 15 min 4: 74 percent / butyl-lithium / hexane; tetrahydrofuran / 2 h / 0 °C 5: 1.) 9-borabicyclo<3.3.1>nonane, 2.) 1M aq. NaOH, 30percent aq. hydrogen peroxide / 1.) THF, 4 h, reflux, 2.) 0 deg C, 30 min 6: 1.) dimethyl sulphoxide, oxalyl chloride, 2.) triethylamine / 1.) CH2Cl2, -60 deg C, 10 min, 2.) -60 deg C, 15 min, room temperature, 15 min 7: 1.) butyl-lithium, 2.) hexamethylphosphoric triamide / 1.) THF, -78 deg C, 2 h, 2.) room temperature, 3 h 8: 98 percent / sodium hydroxide / methanol; H2O / 3 h / Ambient temperature 9: 95 percent / tetrahydrofuran / 12 h 10: 87 percent / lithium hexamethyldisilazide / tetrahydrofuran; hexane / 7 h / -78 °C 11: 95 percent / lithium hexamethyldisilazide / tetrahydrofuran; hexane / 2 h / -78 °C 12: m-chloroperoxybenzoic acid, 30percent aq. hydrogen peroxide / CDCl3 / 1.) -50 deg C, 15 min, 2.) 0 deg C, 15 min 13: 37 percent / toluene / 5 h / 100 °C 14: 98 percent / sodium hydroxide / H2O; methanol / 2 h / 0 °C 15: 98 percent / lithium di-isopropylamide / tetrahydrofuran; hexane / 2 h 16: 78 percent / tetrabutylammonium fluoride / tetrahydrofuran / 2 h / 0 °C 17: 68 percent / pyridine, 30percent aq. hydrogen peroxide / CH2Cl2 / 12 h / Ambient temperature 18: 72 percent / sodium borohydride / ethanol / 3 h / 0 °C 19: 94 percent / pyridine, 4-dimethylaminopyridine / CH2Cl2 / 2 h / Ambient temperature 20: 19 percent / m-chloroperoxybenzoic acid / CH2Cl2 / 1.) -20 deg C, 1 h, 2.) 0 deg C, 12 h 21: 67 percent / aluminium isopropoxide / o-xylene / 5 h / 125 °C 22: 40 percent / 5percent aq. HF / acetonitrile / 3 h / Ambient temperature View Scheme

Multi-step reaction with 5 steps 1: 70 percent / Dowex 50W-X8 2: 95 percent / H2 / Pd/C / methanol3: 90 percent / DMSO, oxalyl chloride4: 70 percent5: 1.) 9-BBN, 2.) H2O2, base  

Multi-step reaction with 7 steps 1: 70 percent / Dowex 50W-X8 2: 95 percent / H2 / Pd/C / methanol3: 90 percent / DMSO, oxalyl chloride4: 70 percent5: 1.) 9-BBN, 2.) H2O2, base6: 90 percent / DMSO, oxalyl chloride  

Multi-step reaction with 9 steps 1: 70 percent / Dowex 50W-X8 2: 95 percent / H2 / Pd/C / methanol3: 90 percent / DMSO, oxalyl chloride4: 70 percent5: 1.) 9-BBN, 2.) H2O2, base6: 90 percent / DMSO, oxalyl chloride8: 90 percent / NaOH / methanol; H2O9: 90 percent  

Multi-step reaction with 11 steps 1: 70 percent / Dowex 50W-X8 2: 95 percent / H2 / Pd/C / methanol3: 90 percent / DMSO, oxalyl chloride4: 70 percent5: 1.) 9-BBN, 2.) H2O2, base6: 90 percent / DMSO, oxalyl chloride8: 90 percent / NaOH / methanol; H2O9: 90 percent10: LiN(SiMe3)211: 95 percent / LiN(SiMe3)2  

Multi-step reaction with 12 steps 1: 70 percent / Dowex 50W-X8 2: 95 percent / H2 / Pd/C / methanol3: 90 percent / DMSO, oxalyl chloride4: 70 percent5: 1.) 9-BBN, 2.) H2O2, base6: 90 percent / DMSO, oxalyl chloride8: 90 percent / NaOH / methanol; H2O9: 90 percent10: LiN(SiMe3)211: 95 percent / LiN(SiMe3)212: MCPBA, H2O2 / 1.) -40 deg C, 15 min, 2.) 0 deg C  

Multi-step reaction with 15 steps 1: 70 percent / Dowex 50W X-8 / methanol / 3 h / Ambient temperature2: 95 percent / hydrogen / 10percent Pd-C / methanol / 4 h / 760 Torr3: 1.) dimethyl sulphoxide, oxalyl chloride, 2.) triethylamine / 1.) CH2Cl2, -60 deg C, 10 min, 2.) -60 deg C, 15 min4: 74 percent / butyl-lithium / hexane; tetrahydrofuran / 2 h / 0 °C5: 1.) 9-borabicyclo<3.3.1>nonane, 2.) 1M aq. NaOH, 30percent aq. hydrogen peroxide / 1.) THF, 4 h, reflux, 2.) 0 deg C, 30 min6: 1.) dimethyl sulphoxide, oxalyl chloride, 2.) triethylamine / 1.) CH2Cl2, -60 deg C, 10 min, 2.) -60 deg C, 15 min, room temperature, 15 min7: 1.) butyl-lithium, 2.) hexamethylphosphoric triamide / 1.) THF, -78 deg C, 2 h, 2.) room temperature, 3 h8: 98 percent / sodium hydroxide / methanol; H2O / 3 h / Ambient temperature9: 95 percent / tetrahydrofuran / 12 h10: 87 percent / lithium hexamethyldisilazide / tetrahydrofuran; hexane / 7 h / -78 °C11: 95 percent / lithium hexamethyldisilazide / tetrahydrofuran; hexane / 2 h / -78 °C12: m-chloroperoxybenzoic acid, 30percent aq. hydrogen peroxide / CDCl3 / 1.) -50 deg C, 15 min, 2.) 0 deg C, 15 min13: 37 percent / toluene / 5 h / 100 °C14: 98 percent / sodium hydroxide / H2O; methanol / 2 h / 0 °C15: 65 percent / m-chloroperoxybenzoic acid / CH2Cl2 / 1.) -20 deg C, 1 h, 2.) 0 deg C, 12 h  

Multi-step reaction with 17 steps 1: 70 percent / Dowex 50W X-8 / methanol / 3 h / Ambient temperature2: 95 percent / hydrogen / 10percent Pd-C / methanol / 4 h / 760 Torr3: 1.) dimethyl sulphoxide, oxalyl chloride, 2.) triethylamine / 1.) CH2Cl2, -60 deg C, 10 min, 2.) -60 deg C, 15 min4: 74 percent / butyl-lithium / hexane; tetrahydrofuran / 2 h / 0 °C5: 1.) 9-borabicyclo<3.3.1>nonane, 2.) 1M aq. NaOH, 30percent aq. hydrogen peroxide / 1.) THF, 4 h, reflux, 2.) 0 deg C, 30 min6: 1.) dimethyl sulphoxide, oxalyl chloride, 2.) triethylamine / 1.) CH2Cl2, -60 deg C, 10 min, 2.) -60 deg C, 15 min, room temperature, 15 min7: 1.) butyl-lithium, 2.) hexamethylphosphoric triamide / 1.) THF, -78 deg C, 2 h, 2.) room temperature, 3 h8: 98 percent / sodium hydroxide / methanol; H2O / 3 h / Ambient temperature9: 95 percent / tetrahydrofuran / 12 h10: 87 percent / lithium hexamethyldisilazide / tetrahydrofuran; hexane / 7 h / -78 °C11: 95 percent / lithium hexamethyldisilazide / tetrahydrofuran; hexane / 2 h / -78 °C12: m-chloroperoxybenzoic acid, 30percent aq. hydrogen peroxide / CDCl3 / 1.) -50 deg C, 15 min, 2.) 0 deg C, 15 min13: 37 percent / toluene / 5 h / 100 °C14: 98 percent / sodium hydroxide / H2O; methanol / 2 h / 0 °C15: 65 percent / m-chloroperoxybenzoic acid / CH2Cl2 / 1.) -20 deg C, 1 h, 2.) 0 deg C, 12 h16: 51 percent / aluminium isopropoxide / o-xylene / 8 h / 125 °C  

Multi-step reaction with 14 steps 1: 70 percent / Dowex 50W-X8 2: 95 percent / H2 / Pd/C / methanol3: 90 percent / DMSO, oxalyl chloride4: 70 percent5: 1.) 9-BBN, 2.) H2O2, base6: 90 percent / DMSO, oxalyl chloride8: 90 percent / NaOH / methanol; H2O9: 90 percent10: LiN(SiMe3)211: 95 percent / LiN(SiMe3)212: MCPBA, H2O2 / 1.) -40 deg C, 15 min, 2.) 0 deg C13: toluene / 5 h / 80 - 100 °C14: 85 percent / KOH / methanol  

Multi-step reaction with 22 steps 1: 70 percent / Dowex 50W X-8 / methanol / 3 h / Ambient temperature2: 95 percent / hydrogen / 10percent Pd-C / methanol / 4 h / 760 Torr3: 1.) dimethyl sulphoxide, oxalyl chloride, 2.) triethylamine / 1.) CH2Cl2, -60 deg C, 10 min, 2.) -60 deg C, 15 min4: 74 percent / butyl-lithium / hexane; tetrahydrofuran / 2 h / 0 °C5: 1.) 9-borabicyclo<3.3.1>nonane, 2.) 1M aq. NaOH, 30percent aq. hydrogen peroxide / 1.) THF, 4 h, reflux, 2.) 0 deg C, 30 min6: 1.) dimethyl sulphoxide, oxalyl chloride, 2.) triethylamine / 1.) CH2Cl2, -60 deg C, 10 min, 2.) -60 deg C, 15 min, room temperature, 15 min7: 1.) butyl-lithium, 2.) hexamethylphosphoric triamide / 1.) THF, -78 deg C, 2 h, 2.) room temperature, 3 h8: 98 percent / sodium hydroxide / methanol; H2O / 3 h / Ambient temperature9: 95 percent / tetrahydrofuran / 12 h10: 87 percent / lithium hexamethyldisilazide / tetrahydrofuran; hexane / 7 h / -78 °C11: 95 percent / lithium hexamethyldisilazide / tetrahydrofuran; hexane / 2 h / -78 °C12: m-chloroperoxybenzoic acid, 30percent aq. hydrogen peroxide / CDCl3 / 1.) -50 deg C, 15 min, 2.) 0 deg C, 15 min13: 37 percent / toluene / 5 h / 100 °C14: 98 percent / sodium hydroxide / H2O; methanol / 2 h / 0 °C15: 65 percent / m-chloroperoxybenzoic acid / CH2Cl2 / 1.) -20 deg C, 1 h, 2.) 0 deg C, 12 h16: 51 percent / aluminium isopropoxide / o-xylene / 8 h / 125 °C18: lithium di-isopropylamide19: tetrabutylammonium fluoride20: hydrogen peroxide, pyridine21: NaBH4 22: pyridine