Step 3 Synthesis of 3-amino-3-methyl-1-butanol: 3-benzylamino-3-methyl-1-butanol (3.86 g, 20.0 mmol) was dissolved in ethanol (80 mL) and 10% palladium carbon catalyst (400 mg) was added. The reaction mixture was stirred for 6 hours at room temperature under hydrogen atmosphere (5 kgf/cm2). Upon completion of the reaction, the catalyst was removed by filtration and the filtrate was concentrated under vacuum. The residue was purified by distillation to afford the colorless oily product 3-amino-3-methyl-1-butanol (2.00 g, 97% yield). The structure of the product was confirmed by 1H-NMR (400 MHz, CDCl3): δ1.21 (6H, s), 1.59 (2H, t, J=5.5 Hz), 2.63-2.76 (3H, br), 3.85 (2H, t, J=5.5 Hz).