反应详情

To a cold solution (10° C.) of 10.000 (48.5 mmol) of 4-acetoxy-trans-cinnamic acid in 72 ml of anhydrous dioxane is added 7.44 ml (53.35 mmol) of triethylamine. Ethyl chloroformate (5.08 ml, 53.35 mmol) in anhydrous dioxane (10 ml) is added to the mixture over 15 minutes with stirring. The resulting mixture is stirred for further 30 minutes at 10°-12° C. and then filtered. The filtrate is dropwise added to a suspension of 2.295 g (60.624 mmol) of powdered sodium borohydride in 100 ml of anhydrous dioxane and 1.22 ml of anhydrous dimethylformamide, and the mixture stirred at 8° C. for one hour. Acetone (7 ml) is added, the mixture stirred for 30 minutes, and 3.47 ml of acetic acid added. The mixture is concentrated in vacuo to about 100 g and extracted with benzene and water. The organic layer is washed with chilled 10% aqueous sodium carbonate and water, successively, dried over anhydrous magnesium sulfate, and concentrated in vacuo to give 4-acetoxy-trans-cinnamylalcohol (I). This is recrystallized from carbon tetrachloride to give 6.673 g of colorless prisms, mp.73.5°-75° C. The mother liquor is concentrated in vacuo and 1.622 g of residue is dissolved in water and hexane. The aqueous layer is extracted with benzene and the benzene layer is washed with chilled 10% aqueous sodium carbonate and water twice, dried over anhydrous magnesium sulfate, and concentrated in vacuo to give 4-acetoxy-trans-cinnamylalcohol (I). This is recrystallized from carbon tetrachloride to give 536 mg of colorless prisms, mp. 73°-74.5° C. Total yield 7.209 g (77.3%). A portion of the product is recrystallized from ether/hexane to give an authentic specimen as prisms having mp. 75°-76° C.

1. stirringThe resulting mixture is stirred for further 30 minutes at 10°-12° C.
2. filtrationfiltered
3. stirringthe mixture stirred at 8° C. for one hour
4. stirringthe mixture stirred for 30 minutes
5. concentrationThe mixture is concentrated in vacuo to about 100 g
6. extractionextracted with benzene and water
7. washThe organic layer is washed
8. temperaturewith chilled 10% aqueous sodium carbonate and water
9. dry with materialsuccessively, dried over anhydrous magnesium sulfate
10. concentrationconcentrated in vacuo