novozyme 435 in toluene T=60°C; 6 h; microwave irradiation;

1: 77 percent / N-bromosuccinimide / acetic acid; H2O / 1 h / 65 °C 2: 61 percent / methylaluminum dichloride / CH2Cl2 / 2 h / -78 °C 3: sodium dithionite; tetrabutylammonium iodide / tetrahydrofuran; H2O / 0.33 h 4: 0.398 g / aqueous potassium hydroxide / tetrahydrofuran / 4 h 5: 74 percent / copper(I) chloride; oxygen / palladium(II) chloride / dimethylformamide; H2O / 24 h / 20 °C 6: triisopropyl borate; (S)-2-(diphenylhydroxymethyl)pyrrolidine; borane-dimethyl sulfide / tetrahydrofuran / 5 h / 20 °C View Scheme

1: 61 percent / methylaluminum dichloride / CH2Cl2 / 2 h / -78 °C 2: sodium dithionite; tetrabutylammonium iodide / tetrahydrofuran; H2O / 0.33 h 3: 0.398 g / aqueous potassium hydroxide / tetrahydrofuran / 4 h 4: 74 percent / copper(I) chloride; oxygen / palladium(II) chloride / dimethylformamide; H2O / 24 h / 20 °C 5: triisopropyl borate; (S)-2-(diphenylhydroxymethyl)pyrrolidine; borane-dimethyl sulfide / tetrahydrofuran / 5 h / 20 °C View Scheme

tri-isopropoxy-borane; (S)-(-)-α,α-diphenyl-2-pyrrolidinemethanol; dimethylsulfide borane complex in tetrahydrofuran T=20°C; 5 h; Title compound not separated from byproducts;