反应 #1951043

反应方程式

tosyl chloride

isopentenol

hexane

→

3-methyl-3-butene-1-yl tosylate

收率 85.3%

溶剂

dichloromethane

dichloromethane

反应条件

后处理

1. 1
   其他is equipped
2. 2
   其他has been carefully dried
3. 3
   workup.ADDITIONare slowly added to this mixture through a septum
4. 4
   其他resulting in the immediate formation of a white precipitate
5. 5
   过滤The mixture is then filtered
6. 6
   浓缩the filtrate concentrated by evaporation under reduced pressure
7. 7
   workup.ADDITIONThe solution is then diluted with diethyl ether
8. 8
   其他Once the solvent has evaporated
9. 9
   其他a yellowish oil is obtained
10. 10
    其他The product is purified by preparative chromatography through a silica column (silica gel 60; eluent: pentane/ethyl acetate 85/15)

实验过程

2.32 mmol (442 mg) of tosyl chloride and 2.55 mmol (312 mg) of 4-(N,N-dimethylamino)pyridine are introduced while stirring with a magnetic stirrer into 5 ml of anhydrous dichloromethane in a glass reaction vessel which is equipped for handling under an inert atmosphere and has been carefully dried. 2.32 mmol (200 mg) of isopentenol dissolved in approx. 1 ml of dichloromethane are slowly added to this mixture through a septum using a syringe. The reaction is monitored by thin-layer chromatography on silica (silica gel 60 F-254; eluent: pentane/ethyl acetate 85/15 vol./vol.; Rf (product)=0.4 and Rf (TsCl)=0.5). After approx. 3 hours' stirring under a nitrogen atmosphere, the reaction mixture is diluted in a large volume of hexane (approx. 100 ml), resulting in the immediate formation of a white precipitate. The mixture is then filtered and the filtrate concentrated by evaporation under reduced pressure. The solution is then diluted with diethyl ether and refiltered. Once the solvent has evaporated, a yellowish oil is obtained. The product is purified by preparative chromatography through a silica column (silica gel 60; eluent: pentane/ethyl acetate 85/15). In this manner, 1.98 mmol (475 mg) of 3-methyl-3-butene-1-yl tosylate (85% isolated yield) are obtained. The compound (colorless oil) is stored at +4° C. in an anhydrous medium.

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