反应详情

To a solution of trans-4-hydroxy-L-proline (35.9 g) and sodium hydroxide (23.9 g) in water (330 ml) was added dropwise a solution of allyl chlorocarbonate (36.3 g) in methylene chloride (250 ml) under ice-cooling, and stirring was continued for 2 hours. Aqueous layer was separated from the reaction mixture, washed twice each with methylene chloride (100 ml), and then acidified by adding concentrated sulfuric acid (25 g) dropwise at a temperature below 30° C. After adding table salt (120 g), the mixture was extracted twice each with ethyl acetate (220 ml). Extract was dried over magnesium sulfate. Distillation of the solvent gave crude crystalline trans-1-allyloxycarbonyl-4-hydroxy-L-proline (62 g). Purification of the crude crystals by repulping with toluene gave trans-1-allyloxycarbonyl-4-hydroxyl-L-proline (56.1 g) having m.p. 93-°94° C.

1. temperaturecooling
2. customAqueous layer was separated from the reaction mixture
3. washwashed twice each with methylene chloride (100 ml)
4. additionby adding concentrated sulfuric acid (25 g) dropwise at a temperature below 30° C
5. additionAfter adding table salt (120 g)
6. extractionthe mixture was extracted twice each with ethyl acetate (220 ml)
7. extractionExtract
8. dry with materialwas dried over magnesium sulfate
9. distillationDistillation of the solvent
10. customgave crude crystalline trans-1-allyloxycarbonyl-4-hydroxy-L-proline (62 g)
11. customPurification of the crude crystals