HCID 54397227, compound → HCID 54427333, compound

HRID 328031Notes

Reaction equation

HRID 328031 reaction equation
[CH2:1]([O:3][C:4](=[O:24])[CH2:5][CH2:6][CH2:7][C:8](=O)[C:9]1[CH:14]=[CH:13][C:12]([OH:15])=[C:11]([CH2:16][CH2:17][C:18]([O:20][CH2:21][CH3:22])=[O:19])[CH:10]=1)[CH3:2]>C(O)(=O)C.[Pd]>[CH2:1]([O:3][C:4](=[O:24])[CH2:5][CH2:6][CH2:7][CH2:8][C:9]1[CH:14]=[CH:13][C:12]([OH:15])=[C:11]([CH2:16][CH2:17][C:18]([O:20][CH2:21][CH3:22])=[O:19])[CH:10]=1)[CH3:2]

Participants

4

Reactant 1

HCID 54397227HCID 54397227, compound

Product 1

HCID 54427333HCID 54427333, compoundYield 57%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 176Acetic AcidSolvent

Procedure

To a solution of 3.91 g (11.6 mmol) of 3-(3-ethoxy-3-oxopropyl)-4-hydroxy-δ-oxobenzenepentanoic acid ethyl ester (from example 140) in 50 mL of acetic acid was added 0.5 g of 10% palladium on carbon, and the resulting mixture was shaken at room temperature and 45 p.s.i. in a Parr shaker for 18.5 hr. The mixture was filtered with suction through a Celite pad and the solids washed with ethyl acetate. The filtrate and washes were combined and concentrated in vacuo. The residue was dissolved in 200 mL of ethanol and treated with 5 mL of concentrated sulfuric acid. The resulting mixture was refluxed for 4 hr and then stirred at room temperature overnight. Most of ethanol was removed in vacuo and the residue was worked-up with ether in the usual manner (the combined ether extracts were additionally washed with saturated aqueous sodium bicarbonate solution). The crude product was purified by flash chromatography on 350 g of silica gel, eluting with hexane-ethyl acetate (4:1) to give 2.13 g (56.7%) of the title compound as a colorless oil.

Workup

  1. filtrationThe mixture was filtered with suction through a Celite pad
  2. washthe solids washed with ethyl acetate
  3. concentrationconcentrated in vacuo
  4. dissolutionThe residue was dissolved in 200 mL of ethanol
  5. additiontreated with 5 mL of concentrated sulfuric acid
  6. temperatureThe resulting mixture was refluxed for 4 hr
  7. stirringstirred at room temperature overnight
  8. customMost of ethanol was removed in vacuo
  9. washwere additionally washed with saturated aqueous sodium bicarbonate solution)
  10. customThe crude product was purified by flash chromatography on 350 g of silica gel
  11. washeluting with hexane-ethyl acetate (4:1)

Sources & evidence

ORD record
ord-f2323d8868d84f818a69774ac03398bc
Source dataset
uspto-grants-1993_12
Patent number
US05273999

Reaction notes

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