3,4-dihydro-2H-pyran → 1-benzyl 2-ethyl (2S,4R)-4-(tetrahydro-2H-pyran-2-yloxy)-1,2-pyrrolidinedicarboxylate

HRID 2249673Notes

Reaction equation

HRID 2249673 reaction equation
[OH:1][C@H:2]1[CH2:6][N:5]([C:7]([O:9][CH2:10][C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)=[O:8])[C@H:4]([C:17]([O:19][CH2:20][CH3:21])=[O:18])[CH2:3]1.[O:22]1[CH:27]=[CH:26][CH2:25][CH2:24][CH2:23]1.C1(C)C=CC(S([O-])(=O)=O)=CC=1.[NH+]1C=CC=CC=1.C(=O)(O)[O-].[Na+]>C(Cl)Cl>[O:22]1[CH2:27][CH2:26][CH2:25][CH2:24][CH:23]1[O:1][C@H:2]1[CH2:6][N:5]([C:7]([O:9][CH2:10][C:11]2[CH:12]=[CH:13][CH:14]=[CH:15][CH:16]=2)=[O:8])[C@H:4]([C:17]([O:19][CH2:20][CH3:21])=[O:18])[CH2:3]1

Participants

6

Reactant 4

HCID 80803,4-dihydro-2H-pyranHCID 466102Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1)HCID 516892Sodium BicarbonateHCID 146545901-Benzyl 2-ethyl (2S,4R)-4-hydroxypyrrolidine-1,2-dicarboxylate

Product 1

HCID 866300501-benzyl 2-ethyl (2S,4R)-4-(tetrahydro-2H-pyran-2-yloxy)-1,2-pyrrolidinedicarboxylate

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

In 59 ml of methylene chloride are dissolved 11.8 g of 1-benzyl 2-ethyl (2S,4R)-4-hydroxy-1,2-pyrrolidinedicarboxylate, 11 ml of 3,4-dihydropyrane and 2.0 g of pyridinium p-toluenesulfonate. The solution is heated under reflux for one hour. The reaction mixture is added to 50 ml of saturated aqueous solution of sodium bicarbonate, and the organic layer is separated. The organic layer is washed with water and saturated aqueous solution of sodium chloride successively and dried over anhydrous magnesium sulfate, and then the solvent is distilled off under reduced pressure. The residue thus obtained is purified by silica gel column chromatography (eluent; n-hexane:ethyl acetate=2:1) to obtain 12.9 g of 1-benzyl 2-ethyl (2S,4R)-4-(tetrahydro-2H-pyran-2-yloxy)-1,2-pyrrolidinedicarboxylate as a colorless oily product.

Workup

  1. temperatureThe solution is heated
  2. temperatureunder reflux for one hour
  3. customthe organic layer is separated
  4. washThe organic layer is washed with water and saturated aqueous solution of sodium chloride successively
  5. dry with materialdried over anhydrous magnesium sulfate
  6. distillationthe solvent is distilled off under reduced pressure
  7. customThe residue thus obtained
  8. customis purified by silica gel column chromatography (eluent; n-hexane:ethyl acetate=2:1)

Sources & evidence

ORD record
ord-465d14f5c7f14557b5906b290fa15e1f
Source dataset
uspto-grants-2008_01
Patent number
US07314888B1

Reaction notes

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