1: LiAlH4; (1R,2S)-(-)-N-methylephedrine; 2-ethylaminopyridine / diethyl ether / 3 h / -78 °C 2: 99 percent / 1N HCl / Heating 3: 70 percent / BH3; H2O2; NaOAc / tetrahydrofuran 4: 95 percent / LiOH View Scheme