(1) Preparation of 3-(hydroxymethyl)-1-(tert-butoxycarbonyl)piperidine: To a solution of 3-hydroxymethylpiperidine (1.15 g, 10 mmol) in tetrahydrofuran (15 ml) was added triethylamine (2.8 ml, 20 mmol) at room temperature. Subsequently, a solution of di-tert-butyl dicarbonate (2.62 g, 10 mmol) in tetrahydrofuran (5 ml) was added slowly and dropwise with stirring. The reaction mixture was stirred continuously for 20 hours at room temperature. After completion of the reaction, the solvent was removed by distillation under reduced pressure. The residue was dissolved in ethyl acetate (50 ml), and the organic phase was washed sequentially with water and saturated saline, and then dried with anhydrous sodium sulfate. Finally, the solvent was removed by reduced pressure distillation to afford the target product tert-butyl 3-(hydroxymethyl)piperidine-1-carboxylate (2.15 g, 100% yield) as colorless crystals. The product was confirmed by 1H-NMR (CDCl3) and IR (KBr) characterization.1H-NMR (CDCl3) δ: 1.2-1.4 (2H, m), 1.46 (9H, s), 1.5-1.9 (4H, m), 2.8-3.3 (2H, m), 3.51 (2H, t, J = 6.10 Hz), 3.6-3.9 (2H, m) IR (KBr) cm-1: 3491, 1742, 1674, 1428, 1269, 1177, 1153, 858, 769.
