L-Hydroxyproline → (2S,4R)-1-allyloxycarbonyl-2-carboxy-4-hydroxypyrrolidine

HRID 1109816Notes

Reaction equation

HRID 1109816 reaction equation
[OH:1][C@H:2]1[CH2:6][NH:5][C@H:4]([C:7]([OH:9])=[O:8])[CH2:3]1.[OH-].[Na+].[C:12](Cl)(=[O:17])[O:13][CH2:14][CH:15]=[CH2:16]>O.C(Cl)Cl>[CH2:14]([O:13][C:12]([N:5]1[CH2:6][C@H:2]([OH:1])[CH2:3][C@H:4]1[C:7]([OH:9])=[O:8])=[O:17])[CH:15]=[CH2:16]

Participants

6

Reactant 3

HCID 5810L-HydroxyprolineHCID 14798Sodium HydroxideHCID 18052Allyl chloroformate

Product 1

HCID 18639171(2S,4R)-1-allyloxycarbonyl-2-carboxy-4-hydroxypyrrolidineYield 95.2%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6344DichloromethaneSolvent

Procedure

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.

Workup

  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

Sources & evidence

ORD record
ord-01d4bfd5157d4b47a0d4620674aa9046
Source dataset
uspto-grants-1994_06
Patent number
US05322952

Reaction notes

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