反应详情

n-Butyl lithium (a 2.5M solution in hexane; 28.8 ml, 72 mmol) was added to a solution of morpholine (6.28 ml, 72 mmol) in tetrahydrofuran (700 ml) at -78° under argon. After 20 minutes, 3-furaldehyde (7.0 g, 72 mmol) was added. After another 20 minutes, sec-butyl lithium (a 1.3M solution in cyclohexane; 55.4 ml, 72 mmol) was added dropwise and stirring continued at -78° for 7 hours before trimethylsilyl chloride (27 ml, 216 mmol) was added. Stirring was continued overnight (14 hours) while the cooling bath was allowed to attain room temperature. The solution was poured into ice cold 10% (v/v) hydrochloric acid (200 ml) and after stirring at 0° for 10 minutes, the layers were separated. The aqueous phase was extracted with diethyl ether. All the organic phases were combined, dried (magnesium sulfate) and evaporated to dryness to give a light brown oil, which was purified by flash chromatography on silica using 2% ethyl ether/hexane. Fractions with Rf of about 0.30 (silica, 10% ethyl ether/hexane) on evaporation gave the title aldehyde as a light yellow oil, b.p. 48°-50°/0.25 torr.

1. waitAfter another 20 minutes
2. addition55.4 ml, 72 mmol) was added dropwise
3. additionwas added
4. stirringStirring
5. waitwas continued overnight
6. custom(14 hours)
7. customto attain room temperature
8. stirringafter stirring at 0° for 10 minutes
9. customthe layers were separated
10. extractionThe aqueous phase was extracted with diethyl ether
11. dry with materialdried (magnesium sulfate)
12. customevaporated to dryness
13. customto give a light brown oil, which
14. customwas purified by flash chromatography on silica using 2% ethyl ether/hexane
15. customFractions with Rf of about 0.30 (silica, 10% ethyl ether/hexane) on evaporation