Oxalic Acid → 3-(Tetrahydro-2H-pyran-2-yl)-acrolein

HRID 867106Notes

Reaction equation

HRID 867106 reaction equation
[Li].C(=N[CH:5]1[CH2:10][CH2:9][CH2:8][CH2:7][CH2:6]1)C.[C:11](O)(=O)[C:12](O)=[O:13].CC[O:19]CC>O>[O:13]1[CH2:12][CH2:11][CH2:5][CH2:10][CH:9]1[CH:8]=[CH:7][CH:6]=[O:19]

Participants

6

Reactant 4

HCID 971Oxalic AcidHCID 3283Diethyl Ether2×HCID 3028194LithiumHCID 10964544N-cyclohexylethanimine

Product 1

HCID 736761823-(Tetrahydro-2H-pyran-2-yl)-acrolein

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Procedure

A solution of (tetrahydro-2H-pyran-2-yl)carboxaldehyde (1 molar equivalent) in ether is added to a cold (-70° C.), rapidly-stirred solution of the freshly-generated lithium salt of ethylidenecyclohexylamine (1 molar equivalent) in ether. The resulting reaction mixture is allowed to warm to room temperature, then is maintained at room temperature for 24 hours. After cooling to 0° to 5° C., the reaction mixture is diluted with water, stirred at 0° to 5° C. for 1/2 hour and evaporated in vacuo at 40° to 50° C. leaving a residual oil which is treated with oxalic acid (2 molar equivalents) and water. Steam distillation of this mixture is continued until a clear distillate is obtained. The steam distillate is extracted with ether and the organic extract, dried over sodium sulfate, and filtered. Evaporation of the filtrate in vacuo at 40° C. provides the title compound as a mobile oil.

Workup

  1. customThe resulting reaction mixture
  2. temperatureis maintained at room temperature for 24 hours
  3. temperatureAfter cooling to 0° to 5° C.
  4. customevaporated in vacuo at 40° to 50° C.
  5. customleaving a residual oil which
  6. distillationSteam distillation of this mixture
  7. customis obtained
  8. extractionThe steam distillate is extracted with ether
  9. dry with materialthe organic extract, dried over sodium sulfate
  10. filtrationfiltered
  11. customEvaporation of the filtrate in vacuo at 40° C.

Sources & evidence

ORD record
ord-ace9c592eb86460aadc1096859272f4f
Source dataset
uspto-grants-1978_07
Patent number
US04102888

Reaction notes

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