1.1: (S)-(-)-BTM; trimethylacetic anhydride; N-ethyl-N,N-diisopropylamine / diethyl ether / 12 h / 20 °C / Inert atmosphere; Resolution of racemate 2.1: sodium hydride / N,N-dimethyl-formamide; paraffin / 1 h / 0 °C / Inert atmosphere 2.2: 0.67 h / 0 - 20 °C / Inert atmosphere 3.1: benzo[1,3,2]dioxaborole / tetrahydrofuran / 3.5 h / 0 - 70 °C / Inert atmosphere 3.2: 0.17 h / 0 °C / pH 7 / Inert atmosphere; aq. phosphate buffer 3.3: 3 h / 20 °C / Inert atmosphere 4.1: TiCl2(OPri)2 / toluene / 0.25 h / -78 °C / Inert atmosphere 4.2: 4 h / -78 °C / Inert atmosphere 5.1: lithium hexamethyldisilazane / tetrahydrofuran / 1.5 h / -78 - -45 °C / Inert atmosphere 5.2: 3 h / -45 °C / Inert atmosphere 6.1: water; lithium hydroxide hydrate / tetrahydrofuran; methanol / 2 h / 20 - 55 °C / Inert atmosphere 7.1: 4-(N,N-dimethlyamino)pyridine; (2,6-Me(NO2)PhCO)2O; sodium hydrogencarbonate; triethylamine / dichloromethane; water / 12 h / 0 - 20 °C / Inert atmosphere 8.1: 10 palladium on activated charcoal; hydrogen / ethanol / 2 h / 20 °C / Inert atmosphere View Scheme

1.1: (S)-(-)-BTM; trimethylacetic anhydride; N-ethyl-N,N-diisopropylamine / diethyl ether / 12 h / 20 °C / Inert atmosphere; Resolution of racemate 2.1: sodium hydride / N,N-dimethyl-formamide; paraffin / 1 h / 0 °C / Inert atmosphere 2.2: 0.67 h / 0 - 20 °C / Inert atmosphere 3.1: benzo[1,3,2]dioxaborole / tetrahydrofuran / 3.5 h / 0 - 70 °C / Inert atmosphere 3.2: 0.17 h / 0 °C / pH 7 / Inert atmosphere; aq. phosphate buffer 3.3: 3 h / 20 °C / Inert atmosphere 4.1: TiCl2(OPri)2 / toluene / 0.25 h / -78 °C / Inert atmosphere 4.2: 4 h / -78 °C / Inert atmosphere 5.1: lithium hexamethyldisilazane / tetrahydrofuran / 1.5 h / -78 - -45 °C / Inert atmosphere 5.2: 3 h / -45 °C / Inert atmosphere 6.1: water; lithium hydroxide hydrate / tetrahydrofuran; methanol / 2 h / 20 - 55 °C / Inert atmosphere 7.1: 4-(N,N-dimethlyamino)pyridine; (2,6-Me(NO2)PhCO)2O; sodium hydrogencarbonate; triethylamine / dichloromethane; water / 12 h / 0 - 20 °C / Inert atmosphere 8.1: 10 palladium on activated charcoal; hydrogen / ethanol / 2 h / 20 °C / Inert atmosphere 9.1: di-isopropyl azodicarboxylate; triphenylphosphine / tetrahydrofuran; toluene / 3 h / 0 - 20 °C / Inert atmosphere View Scheme

1.1: (S)-(-)-BTM; trimethylacetic anhydride; N-ethyl-N,N-diisopropylamine / diethyl ether / 12 h / 20 °C / Inert atmosphere; Resolution of racemate 2.1: sodium hydride / N,N-dimethyl-formamide; paraffin / 1 h / 0 °C / Inert atmosphere 2.2: 0.67 h / 0 - 20 °C / Inert atmosphere 3.1: benzo[1,3,2]dioxaborole / tetrahydrofuran / 3.5 h / 0 - 70 °C / Inert atmosphere 3.2: 0.17 h / 0 °C / pH 7 / Inert atmosphere; aq. phosphate buffer 3.3: 3 h / 20 °C / Inert atmosphere 4.1: TiCl2(OPri)2 / toluene / 0.25 h / -78 °C / Inert atmosphere 4.2: 4 h / -78 °C / Inert atmosphere 5.1: lithium hexamethyldisilazane / tetrahydrofuran / 1.5 h / -78 - -45 °C / Inert atmosphere 5.2: 3 h / -45 °C / Inert atmosphere 6.1: water; lithium hydroxide hydrate / tetrahydrofuran; methanol / 2 h / 20 - 55 °C / Inert atmosphere 7.1: 4-(N,N-dimethlyamino)pyridine; (2,6-Me(NO2)PhCO)2O; sodium hydrogencarbonate; triethylamine / dichloromethane; water / 12 h / 0 - 20 °C / Inert atmosphere 8.1: 10 palladium on activated charcoal; hydrogen / ethanol / 2 h / 20 °C / Inert atmosphere View Scheme