反应详情

A suspension of 136 (2.69 g, 9.79 mmol), ethylene glycol (2.184 mL, 39.2 mmol), and (1R)-(−)-10-camphorsulfonic acid (0.227 g, 0.979 mmol) in toluene (150 mL) was heated to reflux with a Dean-Stark trap. After 3 h, the mixture was cooled down and filtered through celite (while still warm). The filtrate was washed with water, NaHCO3 (aq., sat.), NaOH (aq) and brine. The solution was then dried over MgSO4 and concentrated to afford compound 137 (2.77 g, 89% yield) as an off-white solid. MS (m/z): 319.1 (M+H).

1. temperaturewas heated
2. temperatureto reflux with a Dean-Stark trap
3. temperaturethe mixture was cooled down
4. filtrationfiltered through celite (
5. temperaturewhile still warm)
6. washThe filtrate was washed with water, NaHCO3 (aq., sat.), NaOH (aq) and brine
7. dry with materialThe solution was then dried over MgSO4
8. concentrationconcentrated