반응 #56554

반응 방정식

Lithium Borohydride

retinal

hydrochloric acid

→

beta-carotene

수율 60.0%

용매

tetrahydrofuran

반응 조건

후처리

1. 1
   기타A solution was prepared
2. 2
   온도the reaction was refluxed for four hours
3. 3
   추출was extracted several times with ether
4. 4
   세척washed with saturated aqueous sodium chloride solution
5. 5
   건조dried over magnesium sulfate
6. 6
   농축concentrated by solvent removal at the rotary evaporator
7. 7
   기타The residue was further purified by chromatography on silica gel
8. 8
   세척Elution with hexane

실험 절차

A solution was prepared by dissolving titanium tetrachloride (1.10 ml, 10.0 mmol) in 25 ml dry tetrahydrofuran under an inert atmosphere. Lithium Borohydride (110 mg, 5.0 mmol) was added, and the resulting solution was stirred at 50° for two hours. A solution of retinal (1.42 gm, 5.0 mmol) 5 ml dry tetrahydrofuran was added, and the reaction was refluxed for four hours. After this, the solution was poured into 50 ml 2 N aqueous hydrochloric acid, and was extracted several times with ether. The ether extracts were combined, washed with saturated aqueous sodium chloride solution, dried over magnesium sulfate, and concentrated by solvent removal at the rotary evaporator. The residue was further purified by chromatography on silica gel. Elution with hexane gave 0.8 gm (60%) beta-carotene, identified by comparison with an authentic sample; mp 180°-182°.

출처