反应详情

温度

78 °C

Following a modified procedure of Clegg et al.,28 lithium hexamethyldisilizade (LiHMDS, 1 M in THF, 1.5 ml, 1.5 mmol) was added to a flame-dried round bottom flask containing THF (20.0 mL) at 78° C. Ethyl acetate (0.15 ml, 1.5 mmol) was then added slowly at 78° C. and stirred at 78° C. for 30 minutes. 36 (0.415 g, 1.15 mmol) was then dissolved in THF (10.0 mL) and added at 78° C., at which point the reaction was allowed to warm to room temperature, and was stirred at room temperature for 4 h. The reaction was monitored by TLC (CH2Cl2) for disappearance of the less polar starting material. More LiHMDS (2.0 mL, 2.0 mmol) and EtOAc (0.70 mL, 0.70 mmol) were added and the reaction was monitored for the disappearance of starting material. When no starting material was present, 10 hours, the reaction was then poured into water, extracted with ethyl acetate, washed with brine, dried over MgSO4, filtered, and condensed. The product was the purified by column chromatography (CH2Cl2 to 1:19 EtOAc:CH2Cl2) to provide 67a (0.361 g, 0.983 mmol, 86%) as a yellow oil.

1. additionwas added to a flame-dried round bottom flask
2. additionadded at 78° C., at which
3. temperatureto warm to room temperature
4. stirringwas stirred at room temperature for 4 h
5. waitWhen no starting material was present, 10 hours
6. extractionextracted with ethyl acetate
7. washwashed with brine
8. dry with materialdried over MgSO4
9. filtrationfiltered
10. customcondensed
11. custompurified by column chromatography (CH2Cl2 to 1:19 EtOAc:CH2Cl2)