Benzaldehyde → 2,8-Dibenzylcyclooctan-1-one

HRID 1578510Notes

Reaction equation

HRID 1578510 reaction equation
[C:1]1(=[O:9])[CH2:8][CH2:7][CH2:6][CH2:5][CH2:4][CH2:3][CH2:2]1.[CH:10](=O)[C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1.[OH-].[K+].CO>CCOCC.O>[CH2:10]([CH:2]1[CH2:3][CH2:4][CH2:5][CH2:6][CH2:7][CH:8]([CH2:10][C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)[C:1]1=[O:9])[C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1

Participants

7

Reactant 4

HCID 240BenzaldehydeHCID 887MethanolHCID 10403CyclooctanoneHCID 14797Potassium Hydroxide

Product 1

HCID 1981842,8-Dibenzylcyclooctan-1-one

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 3283Diethyl EtherSolvent

Procedure

2,8-Dibenzylcyclooctanone is prepared by stirring 25 grams of cyclooctanone, 54 grams of benzaldehyde, 30 grams of potassium hydroxide and 500 milliliters of methanol at reflux temperatures for 4 hours. The mixture is then cooled to room temperature and 200 milliliters of water are added followed by 300 milliliters of ether. The ether layer is separated and the ether and methanol are then removed by distillation. The residue is taken up in 200 milliliters of ethanol and hydrogenated at 1,000 p.s.i.g. and ambient temperature using a 10 percent palladium on carbon catalyst. The catalyst is removed by filtration and the solvent is removed by distillation. Recrystallization of the crude product is effected by dissolving in 150 milliliters of methanol and seeding with crystalline 2,8-dibenzylcyclooctanone (m.p. 75°-77° C.). Cooling of the seeded methanolic solution gives 16 grams of crystals with melting point 60°-67° C. A second recrystallization of this material from methanol gives one isomer of 2,8-dibenzylcyclooctanone, melting point 75°-77° C., as a first crop and a second isomer of 2,8-dibenzylcyclooctanone, melting point 66°-68° C., as a second crop.

Workup

  1. temperatureat reflux temperatures for 4 hours
  2. customThe ether layer is separated
  3. customthe ether and methanol are then removed by distillation
  4. customambient temperature
  5. customThe catalyst is removed by filtration
  6. customthe solvent is removed by distillation
  7. customRecrystallization of the crude product
  8. dissolutionby dissolving in 150 milliliters of methanol
  9. temperatureCooling of the seeded methanolic solution

Sources & evidence

ORD record
ord-58f9bd67e06245718b4a9560fd17a3b7
Source dataset
uspto-grants-1976_02
Patent number
US03937710

Reaction notes

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