1-Diethoxyphosphorylpropan-2-one → 1-(dihydro-2H-pyran-4(3H)-ylidene)propan-2-one

HRID 549235Notes

Reaction equation

HRID 549235 reaction equation
[OH-].[K+].[O:3]1[CH2:8][CH2:7][C:6](=O)[CH2:5][CH2:4]1.[O:10]=[C:11]([CH3:21])[CH2:12]P(=O)(OCC)OCC>C(O)C.O>[O:3]1[CH2:8][CH2:7][C:6](=[CH:12][C:11]([CH3:21])=[O:10])[CH2:5][CH2:4]1

Participants

6

Reactant 3

HCID 140281-Diethoxyphosphorylpropan-2-oneHCID 14797Potassium HydroxideHCID 121599Tetrahydro-4H-pyran-4-one

Product 1

HCID 229657531-(dihydro-2H-pyran-4(3H)-ylidene)propan-2-oneYield 75.9%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 962WaterSolvent

Procedure

A solution of potassium hydroxide (4.66 g, 83.1 mmol) in ethanol (181 mL) and water (45 mL) was cooled to approximately 0° C. Tetrahydro-4H-pyran-4-one (7.56 g, 75.5 mmol) and diethyl (2-oxopropyl)phosphonate (16.1 g, 83.1 mmol) were sequentially added. The reaction was allowed to warm to room temperature and stirred for five hours. The reaction mixture was washed with brine and the organic layer was separated. The aqueous layer was extracted three times with tert-butyl methyl ether. The combined organic fractions were dried over magnesium sulfate, filtered, and concentrated under reduced pressure. The residue was dissolved in a mixture of 20% ethyl acetate in hexane and chloroform, dried again over magnesium sulfate, filtered, concentrated under reduced pressure, and purified by automated flash chromatography (eluting with 35% to 45% ethyl acetate in hexane). The resulting colorless oil was dried under a stream of nitrogen to provide 8.03 g of 1-tetrahydro-4H-pyran-4-ylideneacetone.

Workup

  1. washThe reaction mixture was washed with brine
  2. customthe organic layer was separated
  3. extractionThe aqueous layer was extracted three times with tert-butyl methyl ether
  4. dry with materialThe combined organic fractions were dried over magnesium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated under reduced pressure
  7. dissolutionThe residue was dissolved in a mixture of 20% ethyl acetate in hexane and chloroform
  8. dry with materialdried again over magnesium sulfate
  9. filtrationfiltered
  10. concentrationconcentrated under reduced pressure
  11. custompurified by automated flash chromatography (eluting with 35% to 45% ethyl acetate in hexane)
  12. customThe resulting colorless oil was dried under a stream of nitrogen

Sources & evidence

ORD record
ord-5ff9f2ac46ff44619c022ac0afc6e7e0
Source dataset
uspto-grants-2011_05
Patent number
US07943636B2

Reaction notes

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