Citric Acid → 1,2-dibenzyl 1-tert.butyl 4-methyl-1-(3-phenylprop-2-en-1-yl)-1,1,2-(R)-pentanetricarboxylate

HRID 1464358Notes

Reaction equation

HRID 1464358 reaction equation
[H-].[Na+].[CH3:3][CH:4]([CH3:35])[CH2:5][C@@H:6]([C:25]([O:27][CH2:28][C:29]1[CH:34]=[CH:33][CH:32]=[CH:31][CH:30]=1)=[O:26])[CH:7]([C:18]([O:20][C:21]([CH3:24])([CH3:23])[CH3:22])=[O:19])[C:8]([O:10][CH2:11][C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)=[O:9].[CH2:36](Br)[CH:37]=[CH:38][C:39]1[CH:44]=[CH:43][CH:42]=[CH:41][CH:40]=1.C(O)(=O)CC(CC(O)=O)(C(O)=O)O>CN(C)C=O>[CH3:3][CH:4]([CH3:35])[CH2:5][C@@H:6]([C:25]([O:27][CH2:28][C:29]1[CH:30]=[CH:31][CH:32]=[CH:33][CH:34]=1)=[O:26])[C:7]([CH2:36][CH:37]=[CH:38][C:39]1[CH:44]=[CH:43][CH:42]=[CH:41][CH:40]=1)([C:18]([O:20][C:21]([CH3:24])([CH3:23])[CH3:22])=[O:19])[C:8]([O:10][CH2:11][C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)=[O:9]

Participants

6

Reactant 4

HCID 311Citric AcidHCID 24758Sodium hydrideHCID 98116BromomethylstyreneHCID 18660804Dibenzyl 3(RS)-tert-butoxycarbonyl-2(R)-isobutylsuccinate

Product 1

HCID 678264841,2-dibenzyl 1-tert.butyl 4-methyl-1-(3-phenylprop-2-en-1-yl)-1,1,2-(R)-pentanetricarboxylateYield 95.9%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

0.048 g of 60% sodium hydride was added to a stirred solution of 0.45 g of 1,2-dibenzyl 1-tert-butyl 4-methyl-1,1,2-(R)-pentanetricarboxylate in 10 ml of dry dimethylformamide under a nitrogen atmosphere. The mixture was stirred for 0.75 hour at 0° and for a further 2.5 hours at room temperature. The mixture was again cooled to 0° before the addition of 0.236 g of cinnamyl bromide. After allowing the mixture to return slowly to room temperature, the solution was stirred at room temperature for 2 days. The mixture was poured into 5% aqueous citric acid solution and the product was extracted four times with diethyl ether. The combined ether extracts were washed with water and sodium chloride solution and dried over anhydrous magnesium sulfate. The solvent was removed by evaporation and the residue was purified by flash chromatography on silica gel using hexane/ether (9:1) for the elution. There was obtained 0.542 g of 1,2-dibenzyl 1-tert.butyl 4-methyl-1-(3 -phenylprop-2-en-1-yl)-1,1,2-(R)-pentanetricarboxylate in the form of a colorless oil; MS: 571 (M+H)+.

Workup

  1. customto return slowly to room temperature
  2. stirringthe solution was stirred at room temperature for 2 days
  3. extractionthe product was extracted four times with diethyl ether
  4. washThe combined ether extracts were washed with water and sodium chloride solution
  5. dry with materialdried over anhydrous magnesium sulfate
  6. customThe solvent was removed by evaporation
  7. customthe residue was purified by flash chromatography on silica gel
  8. washfor the elution

Sources & evidence

ORD record
ord-fda71cb59c8b45ae943d6d0bf7eb488c
Source dataset
uspto-grants-1994_04
Patent number
US05304549

Reaction notes

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