Water → Ethyl 4-oxo-3,4-dihydro-2H-pyran-2-carboxylate

HRID 1264039Notes

Reaction equation

HRID 1264039 reaction equation
[CH3:1][O:2][CH:3]=[CH:4][C:5]([O:7][Si](C)(C)C)=[CH2:6].[C:12]([O:16][CH2:17][CH3:18])(=[O:15])C=O.O.FC(F)(F)C(O)=O>C1COCC1.C1(C)C=CC=CC=1>[CH2:17]([O:16][C:12]([CH:1]1[CH2:6][C:5](=[O:7])[CH:4]=[CH:3][O:2]1)=[O:15])[CH3:18]

Participants

7

Reactant 4

HCID 962WaterHCID 6422Trifluoroacetic acidHCID 70211Ethyl oxoacetateHCID 1010511-Methoxy-3-trimethylsilyloxy-1,3-butadiene

Product 1

HCID 22495097Ethyl 4-oxo-3,4-dihydro-2H-pyran-2-carboxylateYield 102.2%

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 8028TetrahydrofuranSolvent

Procedure

ZnCl (0.63 g, 4.6 mmol) was dissolved in anhydrous THF (15 mL) and added to a solution of 1-methoxy-3-(trimethylsilyloxy)-1,3-butadiene (7.94 g, 46.0 mmol) and ethyl glyoxalate (7.05 g, 69.0 mmol) in toluene (30 mL) at room temperature. After stirring for 30 minutes, water (30 mL) and TFA (trifluoracetic acid) (2 mL) were added and the mixture was stirred vigorously for 20 min. After concentration, the residue was partitioned between EtOAc (200 mL) and water (100 mL). The separated organic layer was washed with brine, dried over sodium sulfate, and concentrated to give 8.0 g (100%) of brown oil which was carried to the next step without further purification. 1H NMR (CDCl3) δ 1.30 (t, 3H), 2.85 (d, 2H), 4.26 (q, 2H), 5.00 (t, 1H), 5.48 (d, 1H), 7.39 (d, 1H).

Workup

  1. stirringthe mixture was stirred vigorously for 20 min
  2. concentrationAfter concentration
  3. customthe residue was partitioned between EtOAc (200 mL) and water (100 mL)
  4. washThe separated organic layer was washed with brine
  5. dry with materialdried over sodium sulfate
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-023cdeb999264b938fe982d8f379fd8a
Source dataset
uspto-grants-2003_04
Patent number
US06541481B2

Reaction notes

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