Resolution of racemate;

1: 97 percent / SO3*pyridine, Et3N, DMSO / CH2Cl2 / 15 h 2: 43 percent / SeO2, t-BuOOH / 2,2,4-trimethyl-pentane; CH2Cl2 / 48 h 3: 67 percent / molecular sieves 4 Angstroem / diethyl ether / 10 h 4: 86 percent / p-TsOH*H2O, H2O / tetrahydrofuran / 1 h 5: 60 percent / silver carbonate, Celite / benzene / 2 h / Heating View Scheme

toluene-4-sulfonic acid in cyclohexane 6 h; Heating; Yield given;

1: 77 percent / KHSO4 / cyclohexane / 6 h / Heating 2: 92 percent / PPTS / benzene / 25 h / Heating 3: 1.) borane*THF komplex, 2.) 3 N aq. KOH, 30 percent H2O2 / 1.) THF, 0 deg C, 2 h, 2.) H2O, 0 deg C, 2 h 4: 1.09 g / oxalyl chloride, dimethyl sulfoxide / CH2Cl2 / 0.25 h / -60 °C 5: 89 percent / K2CO3 / methanol / 12 h / 0 °C 6: 98 percent / NaBH4 / ethanol / 0.5 h / 0 °C 7: 99 percent / pyridine / 13 h / Ambient temperature 8: LiAlH4 / tetrahydrofuran / 2 h / Heating 9: 10 percent aq. HCl / tetrahydrofuran / 8 h / Ambient temperature 10: 96 percent / 1.) 1.2 M butyl lithium, diisopropylamine / hexane; tetrahydrofuran / 0.25 h / -78 °C 11: 1.) ozone, 2.) dimethyl sulfide / 1.) MeOH/CH2Cl2, -78 deg C, 2.) -78 deg C, 0.5 h; r. t., 3 h 12: p-TsOH*H2O / cyclohexane / 6 h / Heating View Scheme

1: 92 percent / PPTS / benzene / 25 h / Heating 2: 1.) borane*THF komplex, 2.) 3 N aq. KOH, 30 percent H2O2 / 1.) THF, 0 deg C, 2 h, 2.) H2O, 0 deg C, 2 h 3: 1.09 g / oxalyl chloride, dimethyl sulfoxide / CH2Cl2 / 0.25 h / -60 °C 4: 89 percent / K2CO3 / methanol / 12 h / 0 °C 5: 98 percent / NaBH4 / ethanol / 0.5 h / 0 °C 6: 99 percent / pyridine / 13 h / Ambient temperature 7: LiAlH4 / tetrahydrofuran / 2 h / Heating 8: 10 percent aq. HCl / tetrahydrofuran / 8 h / Ambient temperature 9: 96 percent / 1.) 1.2 M butyl lithium, diisopropylamine / hexane; tetrahydrofuran / 0.25 h / -78 °C 10: 1.) ozone, 2.) dimethyl sulfide / 1.) MeOH/CH2Cl2, -78 deg C, 2.) -78 deg C, 0.5 h; r. t., 3 h 11: p-TsOH*H2O / cyclohexane / 6 h / Heating View Scheme

1: 1.) borane*THF komplex, 2.) 3 N aq. KOH, 30 percent H2O2 / 1.) THF, 0 deg C, 2 h, 2.) H2O, 0 deg C, 2 h 2: 1.09 g / oxalyl chloride, dimethyl sulfoxide / CH2Cl2 / 0.25 h / -60 °C 3: 89 percent / K2CO3 / methanol / 12 h / 0 °C 4: 98 percent / NaBH4 / ethanol / 0.5 h / 0 °C 5: 99 percent / pyridine / 13 h / Ambient temperature 6: LiAlH4 / tetrahydrofuran / 2 h / Heating 7: 10 percent aq. HCl / tetrahydrofuran / 8 h / Ambient temperature 8: 96 percent / 1.) 1.2 M butyl lithium, diisopropylamine / hexane; tetrahydrofuran / 0.25 h / -78 °C 9: 1.) ozone, 2.) dimethyl sulfide / 1.) MeOH/CH2Cl2, -78 deg C, 2.) -78 deg C, 0.5 h; r. t., 3 h 10: p-TsOH*H2O / cyclohexane / 6 h / Heating View Scheme

1: LiAlH4 / tetrahydrofuran / 2 h / Heating 2: 10 percent aq. HCl / tetrahydrofuran / 8 h / Ambient temperature 3: 96 percent / 1.) 1.2 M butyl lithium, diisopropylamine / hexane; tetrahydrofuran / 0.25 h / -78 °C 4: 1.) ozone, 2.) dimethyl sulfide / 1.) MeOH/CH2Cl2, -78 deg C, 2.) -78 deg C, 0.5 h; r. t., 3 h 5: p-TsOH*H2O / cyclohexane / 6 h / Heating View Scheme

1: 96 percent / 1.) 1.2 M butyl lithium, diisopropylamine / hexane; tetrahydrofuran / 0.25 h / -78 °C 2: 1.) ozone, 2.) dimethyl sulfide / 1.) MeOH/CH2Cl2, -78 deg C, 2.) -78 deg C, 0.5 h; r. t., 3 h 3: p-TsOH*H2O / cyclohexane / 6 h / Heating View Scheme

1: 1.09 g / oxalyl chloride, dimethyl sulfoxide / CH2Cl2 / 0.25 h / -60 °C 2: 89 percent / K2CO3 / methanol / 12 h / 0 °C 3: 98 percent / NaBH4 / ethanol / 0.5 h / 0 °C 4: 99 percent / pyridine / 13 h / Ambient temperature 5: LiAlH4 / tetrahydrofuran / 2 h / Heating 6: 10 percent aq. HCl / tetrahydrofuran / 8 h / Ambient temperature 7: 96 percent / 1.) 1.2 M butyl lithium, diisopropylamine / hexane; tetrahydrofuran / 0.25 h / -78 °C 8: 1.) ozone, 2.) dimethyl sulfide / 1.) MeOH/CH2Cl2, -78 deg C, 2.) -78 deg C, 0.5 h; r. t., 3 h 9: p-TsOH*H2O / cyclohexane / 6 h / Heating View Scheme

1: 99 percent / pyridine / 13 h / Ambient temperature 2: LiAlH4 / tetrahydrofuran / 2 h / Heating 3: 10 percent aq. HCl / tetrahydrofuran / 8 h / Ambient temperature 4: 96 percent / 1.) 1.2 M butyl lithium, diisopropylamine / hexane; tetrahydrofuran / 0.25 h / -78 °C 5: 1.) ozone, 2.) dimethyl sulfide / 1.) MeOH/CH2Cl2, -78 deg C, 2.) -78 deg C, 0.5 h; r. t., 3 h 6: p-TsOH*H2O / cyclohexane / 6 h / Heating View Scheme