Reaktion #56736

Reaktionsgleichung

(R)-glycidyl tosylate

NaH

2-allyloxy-4-nitrophenol

phenol

→

2-(2-Allyloxy-4-nitrophenoxymethyl)-oxirane

Reaktionsbedingungen

Aufarbeitung

1. 1
   Waschenwashed with 500 mL of hexane
2. 2
   workup.ADDITION1 L of DMF was added
3. 3
   Sonstigeprepared in the previous step
4. 4
   Temperaturthe mixture heated at 70-75° C. under nitrogen overnight
5. 5
   TemperaturUpon cooling
6. 6
   Sonstigethe DMF was removed in vacuum
7. 7
   WaschenThis was washed with 500 mL portions of 2 N HCl, saturated sodium bicarbonate and saturated brine
8. 8
   Trocknendried over sodium sulfate
9. 9
   FiltrationThe mixture was filtered
10. 10
    Einengenconcentrated to an oil in vacuum and column
11. 11
    Sonstigechromatographed on silica gel using 1:1 hexane/methylene chloride as eluent
12. 12
    SonstigeThe impure material was recrystallized from 1.2 L of 10% ethyl acetate/hexane
13. 13
    Sonstigeto give 34 g of pure (homogeneous on silica gel tlc with 1:1 hexane/methylene chloride) (R)-2-(2-allyloxy-4-nitrophenoxymethyl)-oxirane (m.p. 64° C.)

Vorschrift

20 g (0.50 mole) of 60% NaH/mineral oil was placed in a two-liter flask and washed with 500 mL of hexane. 1 L of DMF was added, followed by 77 g (0.40 mole) of the 2-allyloxy-4-nitrophenol prepared in the previous step. Addition of the phenol was performed in portions under argon. After stirring the mixture for 30 minutes at room temperature under argon, 108 g (0.48 moles) of (R)-glycidyl tosylate was added and the mixture heated at 70-75° C. under nitrogen overnight. Upon cooling, the DMF was removed in vacuum and replaced with one liter of methylene chloride. This was washed with 500 mL portions of 2 N HCl, saturated sodium bicarbonate and saturated brine and dried over sodium sulfate. The mixture was filtered, concentrated to an oil in vacuum and column chromatographed on silica gel using 1:1 hexane/methylene chloride as eluent. This gave 43 g of product contaminated with traces of the two starting materials, followed by 21 g of pure product as a pale yellow solid. The impure material was recrystallized from 1.2 L of 10% ethyl acetate/hexane to give 34 g of pure (homogeneous on silica gel tlc with 1:1 hexane/methylene chloride) (R)-2-(2-allyloxy-4-nitrophenoxymethyl)-oxirane (m.p. 64° C.).

Quelle