反应详情

Diisobutylaluminum hydride (1.0N hexane solution, 66 ml) was added dropwise to a solution of 4-ethoxycarbonyl-2-(trans-styryl)oxazole (8.57 g) in dichloromethane (80 ml) at −78° C. After 15 minutes, methanol (11 ml) was added dropwise, and the mixture was warmed to room temperature over 1 hour. The reaction mixture was filtered through Celite, and the resultant pasty substance was dissolved in ethyl acetate (200 ml) and a saturated aqueous solution (200 ml) of ammonium chloride was added, and an organic layer was separated. The water layer was then extracted with dichloromethane (2×100 ml). The resultant organic layers were collected and washed with a saturated aqueous solution (100 ml) of sodium hydrogencarbonate and saturated saline (100 ml), combined with the filtrate obtained by the filtration through Celite and then dried over anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure. The residue was purified by column chromatography on silica gel (dichloromethane:ethyl acetate=5:1→dichloromethane:methanol=10:1) to obtain the title compound (5.86 g) as colorless needle crystals.

1. filtrationThe reaction mixture was filtered through Celite
2. dissolutionthe resultant pasty substance was dissolved in ethyl acetate (200 ml)
3. additiona saturated aqueous solution (200 ml) of ammonium chloride was added
4. customan organic layer was separated
5. extractionThe water layer was then extracted with dichloromethane (2×100 ml)
6. customThe resultant organic layers were collected
7. washwashed with a saturated aqueous solution (100 ml) of sodium hydrogencarbonate and saturated saline (100 ml)
8. customobtained by the filtration through Celite
9. dry with materialdried over anhydrous sodium sulfate
10. distillationthe solvent was distilled off under reduced pressure
11. customThe residue was purified by column chromatography on silica gel (dichloromethane:ethyl acetate=5:1→dichloromethane:methanol=10:1)