反应详情

To a solution of diethyl 3-(N-ethoxycarbonyl-N-ethoxycarbonyloxyamino)-2-(tetrahydro-2H-pyran-2-yloxy)propylphosphonate (5.01 g.) in methylene chloride (10 ml.), was added dropwise trimethylbromosilane (6.73 g.) with stirring under ice-cooling. The mixture was stirred for an hour under ice-cooling and for additional 2 hours at ambient temperature and evaporated under reduced pressure to remove off the solvent and unreacted excess trimethylbromosilane. The residue was dissolved in water (50 ml.), stirred for an hour at ambient temperature and washed twice with chloroform (20 ml. and 10 ml. portions). The combined chloroform washings were extracted with water (30 ml.). The aqueous extract was washed once again with chloroform (5 ml.) and combined with the above-remained aqueous solution and then evaporated to dryness under reduced pressure to give a tarry residue. This residue was dissolved in water (40 ml.) treated with an activated charcoal (300 mg.) and evaporated to dryness under reduced pressure to give oily 3-(N-ethoxycarbonyl-N-hydroxyamino)-2-hydroxypropylphosphonic acid (2.6 g.).

1. temperaturecooling
2. stirringThe mixture was stirred for an hour under ice-
3. customevaporated under reduced pressure
4. customto remove off the solvent and unreacted excess trimethylbromosilane
5. dissolutionThe residue was dissolved in water (50 ml.)
6. stirringstirred for an hour at ambient temperature
7. washwashed twice with chloroform (20 ml. and 10 ml. portions)
8. extractionThe combined chloroform washings were extracted with water (30 ml.)
9. extractionThe aqueous extract
10. washwas washed once again with chloroform (5 ml.)
11. customevaporated to dryness under reduced pressure
12. customto give a tarry residue
13. customevaporated to dryness under reduced pressure