反应详情

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.).

1. washwashed with 500 mL of hexane
2. addition1 L of DMF was added
3. customprepared in the previous step
4. temperaturethe mixture heated at 70-75° C. under nitrogen overnight
5. temperatureUpon cooling
6. customthe DMF was removed in vacuum
7. washThis was washed with 500 mL portions of 2 N HCl, saturated sodium bicarbonate and saturated brine
8. dry with materialdried over sodium sulfate
9. filtrationThe mixture was filtered
10. concentrationconcentrated to an oil in vacuum and column
11. customchromatographed on silica gel using 1:1 hexane/methylene chloride as eluent
12. customThe impure material was recrystallized from 1.2 L of 10% ethyl acetate/hexane
13. customto 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.)