hydrogenchloride; sodium cyanoborohydride in tetrahydrofuran T=20°C; 23 h;

1.1: potassium hydroxide / ethanol / 2 h / 20 °C 1.2: tartaric acid / H2O; CH2Cl2 / 0.17 h / 0 °C 2.1: 1.21 g / TFA / various solvent(s) / 2 h / -20 °C View Scheme

1.1: diisopropylamine; n-BuLi / tetrahydrofuran; hexane / 0.17 h / 0 °C 1.2: 88 percent / tetrahydrofuran; hexane / 3 h / 0 °C 2.1: potassium hydroxide / ethanol / 2 h / 20 °C 2.2: tartaric acid / H2O; CH2Cl2 / 0.17 h / 0 °C 3.1: 1.21 g / TFA / various solvent(s) / 2 h / -20 °C View Scheme