Sulfuric Acid → Spiro[5.5]undec-1-en-3-one

HRID 2070536Notes

Reaction equation

HRID 2070536 reaction equation
[CH:1]1([CH:7]=O)[CH2:6][CH2:5][CH2:4][CH2:3][CH2:2]1.[CH:9]([C:11]([CH3:13])=[O:12])=[CH2:10].S(=O)(=O)(O)O.C(=O)(O)[O-].[Na+]>C1(C)C=CC=CC=1>[CH:7]1[C:1]2([CH2:2][CH2:3][CH2:4][CH2:5][CH2:6]2)[CH2:10][CH2:9][C:11](=[O:12])[CH:13]=1

Participants

6

Reactant 4

HCID 1118Sulfuric AcidHCID 6570Methyl vinyl ketoneHCID 16275CyclohexanecarboxaldehydeHCID 516892Sodium Bicarbonate

Product 1

HCID 323824Spiro[5.5]undec-1-en-3-one

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

To a solution of cyclohexanecarbaldehyde (10.7 mL) in toluene (100 mL) were added successively methyl vinyl ketone (15 mL) and concentrated sulfuric acid (0.1 mL). The reaction mixture was stirred at room temperature for 1 hour and then heated under reflux while stirring for 4 hours. After cooling down to room temperature, saturated aqueous sodium bicarbonate solution was added to the reaction mixture, followed by separation of the organic layer. Then, after the aqueous layer was extracted with toluene, the organic layers were combined, washed with saturated brine, dried and concentrated. The residue was purified by column chromatography on silica gel (ethyl acetate:hexane (volume ratio)=1:20 to 1:12) to give spiro[5.5]undec-1-en-3-one (8.9 g).

Workup

  1. temperatureheated
  2. temperatureunder reflux
  3. stirringwhile stirring for 4 hours
  4. temperatureAfter cooling down to room temperature
  5. customfollowed by separation of the organic layer
  6. extractionThen, after the aqueous layer was extracted with toluene
  7. washwashed with saturated brine
  8. customdried
  9. concentrationconcentrated
  10. customThe residue was purified by column chromatography on silica gel (ethyl acetate:hexane (volume ratio)=1:20 to 1:12)

Sources & evidence

ORD record
ord-c667dc800a4b4c31a7aa8e218538c822
Source dataset
uspto-grants-2012_10
Patent number
US08299296B2

Reaction notes

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