To a stirred solution of tert-butyl (S)-1-azidopropan-2-ylcarbamate (S2-3) (6.0 g, 30 mmol) in ethyl acetate (50.0 mL) was added 10% Pd/C (2.3 g). The reaction mixture was stirred at room temperature under hydrogen atmosphere (1 atm) for 15 hours. Upon completion of the reaction, the mixture was filtered through a diatomaceous earth pad and the diatomaceous earth was washed with ethyl acetate. The filtrate was concentrated under reduced pressure to afford tert-butyl N-[(1R)-2-amino-1-methylethyl]carbamate (S2-4) (4.8 g, 92% yield) as a light yellow solid.1H NMR (400 MHz, DMSO-d6) δ 0.95 (d, J = 6.6 Hz, 3H), 1.36 (s, 9H), 2.49 (m, 2H), 3.32 (m, 1H), 6.49 (br s, 1H).