To a solution of (R)-(-)-3-BOC-4-methoxycarbonyl-2,2-dimethyl-1,3-oxazolidine (435 mg, 1.678 mmol) in tetrahydrofuran (THF, 5 mL) was slowly added 1 M lithium aluminum hydride (LiAlH4, 5 mL, 5.033 mmol) at 0 °C under nitrogen atmosphere. The reaction mixture was stirred at room temperature for 1 hour. Upon completion of the reaction, it was sequentially quenched with water and 10% sodium hydroxide (NaOH) solution and filtered through diatomaceous earth. The filtrate was diluted with ethyl acetate (EtOAc) and washed with saturated brine, dried over anhydrous magnesium sulfate (MgSO4), filtered and concentrated under reduced pressure. The resulting residue was purified by fast column chromatography using 5:1 hexane/ethyl acetate as eluent to afford tert-butyl (R)-4-hydroxymethyl-2,2-dimethyl-oxazolidine-3-carboxylate (383 mg, 99%) as a white solid.
Under nitrogen atmosphere, tert-butyl (R)-4-hydroxymethyl-2,2-dimethyl-oxazolidine-3-carboxylate (383 mg, 1.656 mmol) was dissolved in anhydrous pyridine (4 mL), and toluenesulfonyl chloride (TsCl, 631 mg, 3.312 mmol) was slowly added at 0 °C. The reaction mixture was stirred for 24 hours. After completion of the reaction, the reaction mixture was concentrated under reduced pressure, diluted with ethyl acetate (EtOAc) and washed with saturated brine, dried over anhydrous magnesium sulfate (MgSO4), filtered and concentrated. The product was recrystallized by ethyl acetate-hexane to afford (R)-N-Boc-2,2-dimethyl-4-(hydroxymethyl)oxazolidine (554 mg, 87%).
1H-NMR (300 MHz, CDCl3): δ 1.40 (s, 9H), 1.54 (s, 3H), 2.45 (s, 3H), 3.78-4.20 (m, 5H), 7.40 (d, 2H), 7.81 (d, 2H).
MS (ESI+): m/z 408 ([M + Na]+).
