(4R)-4-(2-methylpropyl)-1,3-oxazolidin-2-one

Conditions: temp:4.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a cooled (4° C.) solution of (R)-2-amino-4-methylpentan-1-ol (2.98 g, 25.4 mmol) and triethylamine (7.6 mL, 54 mmol, 2.1 equiv) in CH2Cl2 (80 mL) was added dropwise a solution of triphosgene (2.52 g, 8.49 mmol, 0.334 equiv) in 10 ml of CH2Cl2 over 30 min. The reaction mixture was stirred at 4° C. for 15 min, warmed up to room temperature and stirred for an additional 1 h. The mixture was treated with saturated NH4Cl (25 mL), followed by CH2Cl2 (50 mL) and the resulting mixture was stirred for 20 min. The layers were separated and the organic layer was washed with water. The combined aqueous layers were extracted with CH2Cl2 (50 mL). The combined organic layers were dried over Na2SO4, filtered and concentrated to give (R)-4-isobutyloxazolidin-2-one (3.22 g) in 88% yield. The crude product was used for the next reaction without purification. 1H NMR (400 MHz, CD3OD) δ 4.53-4.47 (m, 1H), 4.00-3.92 (m, 2H), 1.67 (ddq, J=13, 8.0, 6.5 Hz, 1H), 1.56-1.48 (m, 1H), 1.40-1.32 (m, 1H), 0.95 (d, J=6.1 Hz, 3H), 0.93 (d, J=6.1 Hz, 3H). warmed up to room temperature stirred for an additional 1 h the resulting mixture was stirred for 20 min The layers were separated the organic layer was washed with water The combined aqueous layers were extracted with CH2Cl2 (50 mL) The combined organic layers were dried over Na2SO4 filtered concentrated