Boron trifluoride etherate → (3AS,6aR)-1,3-dibenzyltetrahydro-1H-furo(3,4-d)imidazole-2,4-dione

HRID 463741Notes

Reaction equation

HRID 463741 reaction equation
[CH2:1]([N:8]1[C@H:12]([C:13](OC)=[O:14])[C@H:11]([C:17](O)=[O:18])[N:10]([CH2:20][C:21]2[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=2)[C:9]1=[O:27])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[BH4-].[Na+].B(F)(F)F.CCOCC.C(=O)([O-])[O-].[K+].[K+]>O1CCCC1>[CH2:20]([N:10]1[C@H:11]2[CH2:17][O:18][C:13](=[O:14])[C@H:12]2[N:8]([CH2:1][C:2]2[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=2)[C:9]1=[O:27])[C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1

Participants

6

Reactant 4

HCID 8000Boron trifluoride etherateHCID 11430Potassium CarbonateHCID 4311764Sodium borohydrideHCID 11428617(4R,5S)-1,3-dibenzyl-5-methoxycarbonyl-2-oxoimidazolidine-4-carboxylic acid

Product 1

HCID 119819(3AS,6aR)-1,3-dibenzyltetrahydro-1H-furo(3,4-d)imidazole-2,4-dioneYield 49.7%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of (4R,5S)-1,3-dibenzyl-5-methoxycarbonyl-2-oxoimidazolidine-4-carboxylic acid (mp., 149°-150° C., [α]36525 =+27.4° at c=1 in DMF, 1.84 g) in tetrahydrofuran (15 ml) were added sodium borohydride (226 mg) in small portions at -20° C., and boron trifluoride etherate (1.06 g). The obtained mixture was stirred at the same temperature for 1 hour and at room temperature for 3 hours, poured into ice-water (50 ml), stirred further at room temperature, adjusted to pH 9 with aqueous potassium carbonate and extracted twice with ethyl acetate (50 ml). Organic layer was washed with saturated aqueous sodium chloride solution, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was purified by chromatography on silica gel column to give (3aS,6aR)-1,3-dibenzylhexahydro-1H-furo[3,4-d]imidazole-2,4-dione (0.80 g). M.P., 114°-118° C. [α]D 20 =+59.8° (c=1, CHCl3).

Workup

  1. stirringstirred further at room temperature
  2. extractionextracted twice with ethyl acetate (50 ml)
  3. washOrganic layer was washed with saturated aqueous sodium chloride solution
  4. dry with materialdried over anhydrous magnesium sulfate
  5. concentrationconcentrated under reduced pressure
  6. customThe residue was purified by chromatography on silica gel column

Sources & evidence

ORD record
ord-4574fc0046634e2196eab93a4b8511d6
Source dataset
uspto-grants-1985_10
Patent number
US04544635

Reaction notes

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