反应详情

(1)Ethyl (4S,5R)-3-tert-butoxycarbonyl-2-(4-methoxyphenyl)-4-cyclopropyl-5-oxazolidinecarboxylate (diastereomeric mixture) obtained in Example 6(1) is purified by column chromatography to give ethyl (4S,5R)-3-tert-butoxycarbonyl-2-(4-methoxyphenyl)-4-cyclopropyl-5-oxazolidinecarboxylate. A 87 mg of lithium hydroxide is added under ice-cooling to a solution of 1.03 g of ethyl (4S,5R)-3-tert-butoxycarbonyl-2-(4-methoxyphenyl)-4-cyclopropyl-5-oxazolidinecarboxylate in a mixture of 20 ml of methanol and 10 ml of water. The mixture is stirred at room temperature for 30 minutes. The reaction mixture is evaporated under reduced pressure to remove methanol. The pH of the solution of the residue in ethyl acetate is adjusted to pH 2 with 1N hydrochloric acid under ice-cooling. After the mixture is extracted with ethyl acetate, the extract is washed with brine, dried and evaporated to remove the solvent to give 1.20 g of (4S,5R)-3-tert-butoxycarbonyl-2-(4-methoxyphenyl)-4-cyclopropyl-5-oxazolidinecarboxylic acid quantitatively. ESI-MS(m/z): 386(M+ +Na) IR(neat,cm-1): 3080,1755,1702

1. customThe reaction mixture is evaporated under reduced pressure
2. customto remove methanol
3. temperaturecooling
4. extractionAfter the mixture is extracted with ethyl acetate
5. washthe extract is washed with brine
6. customdried
7. customevaporated
8. customto remove the solvent