Reaktion #2458685

Reaktionsgleichung

acetonitrile methylene chloride

trifluoroacetic acid

tert-butyl [(4R,6S)-6-[[(3,5-di-tert-butyl-4-hydroxyphenyl)thio]methyl]-2,2-dimethyl-1,3-dioxane-4-yl]acetate

→

(4R,6S)-6-[[(3,5-di-tert-butyl-4-hydroxyphenyl)thio]methyl]-4-hydroxytetrahydropyrane-2-one

Ausbeute 83.0%

Lösungsmittel

methylene chloride

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwith cooling with ice
2. 2
   workup.STIRRINGfurther stirred for 2 hours at room temperature
3. 3
   workup.DISTILLATIONThe reaction solution was distilled away under reduced pressure
4. 4
   workup.ADDITIONTo the residue was added toluene
5. 5
   workup.DISTILLATIONagain the mixture was distilled away under reduced pressure
6. 6
   Sonstigethe obtained residue was purified

Vorschrift

In 6.5 ml of anhydrous methylene chloride was dissolved 0.647 g (1.346 mmol) of tert-butyl [(4R,6S)-6-[[(3,5-di-tert-butyl-4-hydroxyphenyl)thio]methyl]-2,2-dimethyl-1,3-dioxane-4-yl]acetate. Thereto was added dropwise 1.3 ml of trifluoroacetic acid with cooling with ice and stirred for a half hour at the same temperature, further stirred for 2 hours at room temperature. The reaction solution was distilled away under reduced pressure. To the residue was added toluene, and again the mixture was distilled away under reduced pressure. After repeating such procedure twice, the obtained residue was purified by subjecting to silica gel column chromatography [eluent: acetonitrile-methylene chloride (1:9 to 1:4)]to give 0.396 g of (4R,6S)-6-[[(3,5-di-tert-butyl-4-hydroxyphenyl)thio]methyl]-4-hydroxytetrahydropyrane-2-one as crystals (yield: 83%). The desired compound was recrystallized from hexane.

Quelle