1.1: N-ethyl-N,N-diisopropylamine / dichloromethane / 2 h / 20 °C / |Cooling with ice; |Inert atmosphere 2.1: AlCl3, aluminium chloride / 1 h / 100 - 170 °C / |Inert atmosphere 3.1: potassium hexamethylsilazane / toluene / 0.33 h / |Inert atmosphere 3.2: 20 °C / |Inert atmosphere 4.1: palladium on activated charcoal; hydrogenchloride; hydrogen / ethanol / 24 h / 3750.38 Torr / |Autoclave View Scheme

1.1: AlCl3, aluminium chloride / 1 h / 100 - 170 °C / |Inert atmosphere 2.1: potassium hexamethylsilazane / toluene / 0.33 h / |Inert atmosphere 2.2: 20 °C / |Inert atmosphere 3.1: palladium on activated charcoal; hydrogenchloride; hydrogen / ethanol / 24 h / 3750.38 Torr / |Autoclave View Scheme

1: With (2S,3S)-(+)-di-O-(p-toluoyl)-tartaric acid in methanol T=20°C; 8 - 72 h; 2: With sodium hydrogencarbonate in ethyl acetate pH=9 - 10; 3: With hydrogenchloride in methanol