Tetrahydrofuran → (S)-4-Methoxymethyl-oxazolidin-2-one

To a stirred solution of tert-butyl [(2R)-1-hydroxy-3-methoxypropan-2-yl]carbamate (synthesized according to the procedure described in Sowinski, J. A.; Toogood, P. L. J. Org. Chem. (1996), 61(22), 7671-7676) (8.3 g, 40.4 mmol) tetrahydrofuran (100 mL), 1M solution of potassium t-butoxide in tetrahydrofuran (80.9 mL, 80.9 mmol) was added dropwise at 0° C. and the mixture was stirred at the room temperature for 2 hours. Water (20 ml) was added to the reaction mixture and extracted with ethyl acetate (3×50 ml). The combined organic layers were washed with brine and dried over Na2SO4. Yield: 5.0 g (94%). 1H NMR (300 MHz, DMSO-d6) δ: 3.3 (s, 3H), 3.3 (m, 2H), 3.9 (m, 1H), 4.0 (dd, 1H), 4.3 (t, 1H), 7.7 (d, 1H). [α]D25=−5.876.