反应详情

温度

0 °C

A solution of 2.45 g of (4S)-N-crotonyl-4-benzyl-2-oxazolidinone in 10 ml of anhydrous CH2Cl2 was cooled to −78° C., and 1.7 ml of triethylamine was added followed by 10.5 ml of a 1 M solution of dibutylboron triflate in CH2Cl2. After 30 minutes, the reaction was warmed to 0° C., kept for 20 minutes, then recooled to −78° C. Propionaldehyde (0.9 ml) was added, and the reaction was allowed to slowly warm to ambient temperature over 16 hours. Standard oxidative workup yielded the product (1.98 g, 65% yield) after chromatography (2:1 hexane/ethyl acetate). 1H-NMR (360 MHz, CDCl3): δ 7.2–7.35 (m,5H); 6.02 (1H,m); 5.41 (m,2H); 4.72 (m,1H); 4.58 (dd,1H); 4.20 (m,2H); 3.92 (m,1H); 3.25 (dd,1H); 2.98 (br s, 1H); 2.76 (dd,1H); 1.53 (m,2H); 0.98 (t,3H).

1. waitkept for 20 minutes
2. customrecooled to −78° C
3. temperatureto slowly warm to ambient temperature over 16 hours