반응 #56549

반응 방정식

retinal

hydrochloric acid

→

beta-carotene

수율 20.0%

용매

tetrahydrofuran

반응 조건

후처리

1. 1
   온도After refluxing for two hours
2. 2
   추출extracted several times with ether
3. 3
   세척washed with saturated aqueous sodium chloride solution, dried sulfate
4. 4
   농축concentrated by solvent removal at the rotary evaporator
5. 5
   기타The residue was purified by chromatography over silica gel
6. 6
   세척Elution with hexane

실험 절차

A slurry of titanium trichloride (770 mg, 5.0 mmol) in 20 ml dry tetrahydrofuran was prepared under an inert atmosphere (nitrogen or argon), and magnesium turnings (120 mg, 5.0 mmol) were added. The resulting mixture was refluxed overnight to form the Ti(II) reagent, and a solution of retinal (710 mg, 2.5 mmol) in 5 ml dry tetrahydrofuran was added. After refluxing for two hours, the solution was poured into 50 ml 2 N aqueous hydrochloric acid and extracted several times with ether. The ether extracts were combined, washed with saturated aqueous sodium chloride solution, dried sulfate, and concentrated by solvent removal at the rotary evaporator. The residue was purified by chromatography over silica gel. Elution with hexane gave 130 mg (20% yield) beta-carotene identified by thin-layer chromatographic comparison with an authentic sample, and by its characteristic ultraviolet spectrum.

출처