反应详情

Sodium metal (1.35 g, 58 mmol) was cut into small pieces, rinsed with hexane to remove mineral oil, and added portion wise to anhydrous EtOH (100 ml) under a nitrogen atmosphere over a period of 20 min. The reaction mixture was stirred for a further 10 min until all sodium had reacted. 1-[2,4-bis(benzyloxy)-5-chlorophenyl]ethanone (10 g, 27.3 mmol) was added portion wise over 5 min, and the resulting suspension was then stirred for further 5 min at RT. Diethyloxalate (6 ml, 43 mmol) was added, resulting in a thick yellow coloured precipitate. The reaction mixture was heated to reflux for 4 h, affording a dark homogeneous solution, which, upon cooling, produced a solid mass to which acetic acid (6 ml) was added. The mixture was triturated to afford a yellow solid, which was filtered, washed sequentially with water, EtOH, and Et2O, and then dried under vacuo to afford the title compound ethyl 4-(2,4-bis(benzyloxy)-5-chlorophenyl)-2-hydroxy-4-oxobut-2-enoate (12.4 g, 98%) as a yellow solid.

1. washrinsed with hexane
2. customto remove mineral oil
3. additionadded portion wise to anhydrous EtOH (100 ml) under a nitrogen atmosphere over a period of 20 min
4. customhad reacted
5. stirringthe resulting suspension was then stirred for further 5 min at RT
6. customresulting in a thick yellow coloured precipitate
7. temperatureThe reaction mixture was heated
8. temperatureto reflux for 4 h
9. customaffording a dark homogeneous solution, which
10. temperatureupon cooling
11. additionwas added
12. customThe mixture was triturated
13. customto afford a yellow solid, which
14. filtrationwas filtered
15. washwashed sequentially with water, EtOH, and Et2O
16. customdried under vacuo