Reaktion #10247

Reaktionsgleichung

hydrochoric acid

2-[(4R,6S)-2,2-dimethyl-6-benzoyloxymethyl-1,3-dioxan-4-yl]acetic tert-butyl ester

sodium hydroxide

→

2-[(4R,6S)-6-(hydroxymethyl)-2,2-dimethyl-1,3-dioxan-4-yl]acetic tert-butyl ester

Ausbeute 90.0%

Lösungsmittel

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturcooling
2. 2
   workup.DISTILLATIONThe methanol was then distilled off under reduced pressure
3. 3
   Extraktionthe residual aqueous solution was extracted with 2 portions of methylene chloride, 70 mL each
4. 4
   workup.DISTILLATIONthe solvent was distilled off under reduced pressure
5. 5
   Sonstigeto give a colorless oil
6. 6
   SonstigeThis residue was purified by silica gel column chromatography (Kieselgel 60, product of Merck; hexane:acetone=5:1)

Vorschrift

To a solution of 3.64 g (10 mmol) of the 2-[(4R,6S)-2,2-dimethyl-6-benzoyloxymethyl-1,3-dioxan-4-yl]acetic tert-butyl ester produced in Example 26 in methanol (36 mL) was added 10 mL of 1N-aqueous sodium hydroxide solution, and the mixture was stirred at room temperature for 2 hours. This reaction mixture was adjusted to pH 7 by gradual addition of 1N-hydrochoric acid under ice-cooling. The methanol was then distilled off under reduced pressure and the residual aqueous solution was extracted with 2 portions of methylene chloride, 70 mL each. The organic layer was dehydrated over anhydrous sodium sulfate and the solvent was distilled off under reduced pressure to give a colorless oil. This residue was purified by silica gel column chromatography (Kieselgel 60, product of Merck; hexane:acetone=5:1) to give 2.34 g of 2-[(4R,6S)-6-(hydroxymethyl)-2,2-dimethyl-1,3-dioxan-4-yl]acetic tert-butyl ester (white solid). Yield 90%.

Quelle