Chloroselenobenzene → Racemic ethyl 2,4-dimethyl-6-oxocyclohex-1-enecarboxylate

HRID 1891995Notes

Reaction equation

HRID 1891995 reaction equation
[CH3:1][CH:2]1[CH2:7][CH:6]([CH3:8])[CH2:5][C:4](=[O:9])[CH:3]1[C:10]([O:12][CH2:13][CH3:14])=[O:11].[H-].[Na+].C1([Se]Cl)C=CC=CC=1.C(=O)(O)[O-].[Na+]>C1COCC1>[CH3:1][C:2]1[CH2:7][CH:6]([CH3:8])[CH2:5][C:4](=[O:9])[C:3]=1[C:10]([O:12][CH2:13][CH3:14])=[O:11]

Participants

6

Reactant 4

HCID 21928ChloroselenobenzeneHCID 24758Sodium hydrideHCID 458120Ethyl 2,4-dimethyl-6-oxocyclohexane-1-carboxylateHCID 516892Sodium Bicarbonate

Product 1

HCID 67159177Racemic ethyl 2,4-dimethyl-6-oxocyclohex-1-enecarboxylateYield 40.4%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
0 °C

Procedure

Ethyl 2,4-dimethyl-6-oxocyclohexanecarboxylate (from Step 2, 0.5 g) was added dropwise to a stirred suspension of sodium hydride (60% in mineral oil, 0.15 g, washed with hexane) in THF at 0° C. After addition was complete, the mixture was stirred at 0° C. for 10 min and then a solution of phenylselenium chloride (0.58 g) in THF was added dropwise. The resulting mixture was slowly warmed to rt where it stirred overnight. After this time, the mixture was treated with saturated aqueous sodium bicarbonate and extracted three times with ethyl acetate. The combined organic layers were concentrated under vacuum and the resulting residue was dissolved in dichloromethane. This solution was treated with 30% aqueous hydrogen peroxide (3×0.3 mL, added at 10 min intervals) and the mixture was stirred for an additional 30 min. At the conclusion of this period, the mixture was washed with water and concentrated under vacuum to yield a residue. This residue was purified by column chromatography on silica gel, eluting with 10% ethyl acetate/hexanes, to provide racemic ethyl 2,4-dimethyl-6-oxocyclohex-1-enecarboxylate as an oil (200 mg).

Workup

  1. additionAfter addition
  2. temperatureThe resulting mixture was slowly warmed to rt where it
  3. stirringstirred overnight
  4. extractionextracted three times with ethyl acetate
  5. concentrationThe combined organic layers were concentrated under vacuum
  6. dissolutionthe resulting residue was dissolved in dichloromethane
  7. additionThis solution was treated with 30% aqueous hydrogen peroxide (3×0.3 mL, added at 10 min intervals)
  8. stirringthe mixture was stirred for an additional 30 min
  9. washAt the conclusion of this period, the mixture was washed with water
  10. concentrationconcentrated under vacuum
  11. customto yield a residue
  12. customThis residue was purified by column chromatography on silica gel
  13. washeluting with 10% ethyl acetate/hexanes

Sources & evidence

ORD record
ord-f6613d69ca2341639a761b055e9ce071
Source dataset
uspto-grants-2013_08
Patent number
US08507559B2

Reaction notes

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