(2R,3S)-(-)-di-O-benzoyl tartaric acid in isopropyl alcohol T=20 - 85°C; 18 h; Inert atmosphere; Reagent/catalyst;

1.1: tetrahydrofuran / 2 h / 20 °C / |Inert atmosphere 2.1: 5 h / 100 °C / |Inert atmosphere 3.1: toluene / 3 h / |Inert atmosphere; |Dean-Stark; |Reflux 3.2: 5 h / |Inert atmosphere; |Dean-Stark; |Reflux 4.1: sodium acetate; acetic acid; bromine / 4 h / 45 °C / |Inert atmosphere 5.1: sodium azide / N,N-dimethyl-formamide / 5 h / 45 °C / |Inert atmosphere 6.1: zinc; ammonium chloride / ethyl acetate; methanol / 0.5 h / 20 - 60 °C / |Inert atmosphere 7.1: (2R,3S)-(-)-di-O-benzoyl tartaric acid / isopropyl alcohol / 18 h / 20 - 85 °C / |Inert atmosphere View Scheme

1.1: tetrahydrofuran / 2 h / 20 °C / |Inert atmosphere 2.1: 5 h / 100 °C / |Inert atmosphere 3.1: toluene / 3 h / |Inert atmosphere; |Dean-Stark; |Reflux 3.2: 5 h / |Inert atmosphere; |Dean-Stark; |Reflux 4.1: sodium acetate; acetic acid; bromine / 4 h / 45 °C / |Inert atmosphere 5.1: sodium azide / N,N-dimethyl-formamide / 5 h / 45 °C / |Inert atmosphere 6.1: zinc; ammonium chloride / ethyl acetate; methanol / 0.5 h / 20 - 60 °C / |Inert atmosphere 7.1: (2R,3S)-(-)-di-O-benzoyl tartaric acid / isopropyl alcohol / 18 h / 20 - 85 °C / |Inert atmosphere View Scheme

1.1: 5 h / 100 °C / |Inert atmosphere 2.1: toluene / 3 h / |Inert atmosphere; |Dean-Stark; |Reflux 2.2: 5 h / |Inert atmosphere; |Dean-Stark; |Reflux 3.1: sodium acetate; acetic acid; bromine / 4 h / 45 °C / |Inert atmosphere 4.1: sodium azide / N,N-dimethyl-formamide / 5 h / 45 °C / |Inert atmosphere 5.1: zinc; ammonium chloride / ethyl acetate; methanol / 0.5 h / 20 - 60 °C / |Inert atmosphere 6.1: (2R,3S)-(-)-di-O-benzoyl tartaric acid / isopropyl alcohol / 18 h / 20 - 85 °C / |Inert atmosphere View Scheme

1.1: toluene / 3 h / |Inert atmosphere; |Dean-Stark; |Reflux 1.2: 5 h / |Inert atmosphere; |Dean-Stark; |Reflux 2.1: sodium acetate; acetic acid; bromine / 4 h / 45 °C / |Inert atmosphere 3.1: sodium azide / N,N-dimethyl-formamide / 5 h / 45 °C / |Inert atmosphere 4.1: zinc; ammonium chloride / ethyl acetate; methanol / 0.5 h / 20 - 60 °C / |Inert atmosphere 5.1: (2R,3S)-(-)-di-O-benzoyl tartaric acid / isopropyl alcohol / 18 h / 20 - 85 °C / |Inert atmosphere View Scheme

1: sodium acetate; acetic acid; bromine / 4 h / 45 °C / |Inert atmosphere 2: sodium azide / N,N-dimethyl-formamide / 5 h / 45 °C / |Inert atmosphere 3: zinc; ammonium chloride / ethyl acetate; methanol / 0.5 h / 20 - 60 °C / |Inert atmosphere 4: (2R,3S)-(-)-di-O-benzoyl tartaric acid / isopropyl alcohol / 18 h / 20 - 85 °C / |Inert atmosphere View Scheme

1: sodium azide / N,N-dimethyl-formamide / 5 h / 45 °C / |Inert atmosphere 2: zinc; ammonium chloride / ethyl acetate; methanol / 0.5 h / 20 - 60 °C / |Inert atmosphere 3: (2R,3S)-(-)-di-O-benzoyl tartaric acid / isopropyl alcohol / 18 h / 20 - 85 °C / |Inert atmosphere View Scheme

1: zinc; ammonium chloride / ethyl acetate; methanol / 0.5 h / 20 - 60 °C / |Inert atmosphere 2: (2R,3S)-(-)-di-O-benzoyl tartaric acid / isopropyl alcohol / 18 h / 20 - 85 °C / |Inert atmosphere View Scheme