1: lithium triethylborohydride / tetrahydrofuran / -78 °C 2: triphenylphosphine; diethylazodicarboxylate / tetrahydrofuran 3: hydrogenchloride / tetrahydrofuran; methanol; water / 55 °C View Scheme

1: lithium triethylborohydride / tetrahydrofuran / -78 °C 2: triphenylphosphine; diethylazodicarboxylate / tetrahydrofuran 3: hydrogenchloride / tetrahydrofuran; methanol; water / 55 °C View Scheme

lithium triethylborohydride in tetrahydrofuran T=-78°C; diastereoselective reaction;