1: With mercaptoacetic acid; N-ethyl-N,N-diisopropylamine in dichloromethane T=0°C; 0.5 h; 2: With sodium carbonate in dichloromethane; water T=20°C; 0.5 h;

1: With mercaptoacetic acid; triethylamine in dichloromethane T=0°C; 0.5 h; 2: With sodium carbonate in dichloromethane; water T=20°C; 0.5 h;

alcohol dehydrogenase from Thermoanaerobium brockii; β-nicotinamide dinucleotide phosphate sodium salt; morphine dehydrogenase from Pseudomonas putida M10 in phosphate buffer T=30°C; 24 h; Title compound not separated from byproducts.;

1: H2 / Pd-C / methanol 2: aq. HCl / 0.5 h / 50 °C View Scheme

1.1: tributylphosphine; diethylazodicarboxylate / tetrahydrofuran; toluene / 0.5 h / 20 °C 2.1: tris-(dibenzylideneacetone)dipalladium(0); triethylamine; tris-(o-tolyl)phosphine / acetonitrile / 1 h / 85 °C 3.1: lithium aluminium tetrahydride / tetrahydrofuran / 1 h / 70 °C 3.2: 0.17 h / 20 °C 4.1: camphor-10-sulfonic acid / methanol / 6 h / 20 °C 5.1: Dess-Martin periodane / dichloromethane / 0.5 h / 40 °C 6.1: trifluoroacetic acid / water; toluene / 2 h / 50 °C 7.1: N-ethyl-N,N-diisopropylamine / dichloromethane / 0.17 h / 0 °C 8.1: mercaptoacetic acid; triethylamine / dichloromethane / 0.5 h / 0 °C 8.2: 0.5 h / 20 °C View Scheme

potassium hydrogensulfate

1.1: tributylphosphine; diethylazodicarboxylate / tetrahydrofuran; toluene / 0.5 h / 20 °C 2.1: tris-(dibenzylideneacetone)dipalladium(0); triethylamine; tris-(o-tolyl)phosphine / acetonitrile / 1 h / 85 °C 3.1: lithium aluminium tetrahydride / tetrahydrofuran / 1 h / 70 °C 3.2: 0.17 h / 20 °C 4.1: camphor-10-sulfonic acid / methanol / 6 h / 20 °C 5.1: Dess-Martin periodane / dichloromethane / 0.5 h / 40 °C 6.1: trifluoroacetic acid / water; toluene / 2 h / 50 °C 7.1: N-ethyl-N,N-diisopropylamine / dichloromethane / 0.17 h / 0 °C 8.1: mercaptoacetic acid; triethylamine / dichloromethane / 0.5 h / 0 °C 8.2: 0.5 h / 20 °C View Scheme

1.1: tris-(dibenzylideneacetone)dipalladium(0); triethylamine; tris-(o-tolyl)phosphine / acetonitrile / 1 h / 85 °C 2.1: lithium aluminium tetrahydride / tetrahydrofuran / 1 h / 70 °C 2.2: 0.17 h / 20 °C 3.1: camphor-10-sulfonic acid / methanol / 6 h / 20 °C 4.1: Dess-Martin periodane / dichloromethane / 0.5 h / 40 °C 5.1: trifluoroacetic acid / water; toluene / 2 h / 50 °C 6.1: N-ethyl-N,N-diisopropylamine / dichloromethane / 0.17 h / 0 °C 7.1: mercaptoacetic acid; triethylamine / dichloromethane / 0.5 h / 0 °C 7.2: 0.5 h / 20 °C View Scheme

1.1: lithium aluminium tetrahydride / tetrahydrofuran / 1 h / 70 °C 1.2: 0.17 h / 20 °C 2.1: camphor-10-sulfonic acid / methanol / 6 h / 20 °C 3.1: Dess-Martin periodane / dichloromethane / 0.5 h / 40 °C 4.1: trifluoroacetic acid / water; toluene / 2 h / 50 °C 5.1: N-ethyl-N,N-diisopropylamine / dichloromethane / 0.17 h / 0 °C 6.1: mercaptoacetic acid; triethylamine / dichloromethane / 0.5 h / 0 °C 6.2: 0.5 h / 20 °C View Scheme

1.1: camphor-10-sulfonic acid / methanol / 6 h / 20 °C 2.1: Dess-Martin periodane / dichloromethane / 0.5 h / 40 °C 3.1: trifluoroacetic acid / water; toluene / 2 h / 50 °C 4.1: N-ethyl-N,N-diisopropylamine / dichloromethane / 0.17 h / 0 °C 5.1: mercaptoacetic acid; triethylamine / dichloromethane / 0.5 h / 0 °C 5.2: 0.5 h / 20 °C View Scheme