2-Acetyl-5-hydroxy-2,3-dihydronaphtho[2,3-b]furan-4,9-dione → 2-Acetyl-5-hydroxy-2,3-dihydronaphtho[2,3-b]furan-4,9-dione

HRID 604943Notes

Reaction equation

HRID 604943 reaction equation
[C:1]([CH:4]1[O:8][C:7]2[C:9](=[O:19])[C:10]3[C:15]([C:16](=[O:17])[C:6]=2[CH2:5]1)=[C:14]([OH:18])[CH:13]=[CH:12][CH:11]=3)(=[O:3])[CH3:2]>C(Cl)(Cl)Cl.[O-2].[O-2].[Mn+4]>[C:1]([C:4]1[O:8][C:7]2[C:9](=[O:19])[C:10]3[C:15]([C:16](=[O:17])[C:6]=2[CH:5]=1)=[C:14]([OH:18])[CH:13]=[CH:12][CH:11]=3)(=[O:3])[CH3:2].[C:1]([CH:4]1[O:8][C:7]2[C:9](=[O:19])[C:10]3[C:15]([C:16](=[O:17])[C:6]=2[CH2:5]1)=[C:14]([OH:18])[CH:13]=[CH:12][CH:11]=3)(=[O:3])[CH3:2]

Participants

5

Reactant 1

HCID 177479482-Acetyl-5-hydroxy-2,3-dihydronaphtho[2,3-b]furan-4,9-dione

Product 2

HCID 100152592-Acetyl-5-hydroxynaphtho[2,3-b]furan-4,9-dioneYield 44%HCID 177479482-Acetyl-5-hydroxy-2,3-dihydronaphtho[2,3-b]furan-4,9-dioneYield 51%

Reagents, catalysts & solvents 2

HCID 178418406HCID 178418406, compoundCatalystHCID 6212ChloroformSolvent

Procedure

To a solution of 2-acetyl-2,3-dihydro-5-hydroxynaphtho[2,3-b]furan-4,9-dione (0.5 g, 1.95 mmol) in chloroform (50 mL) is added 10 g of manganese dioxide (manufactured by Aldrich Corp., 90% manganese dioxide, for battery cell, <10 micron), and the resulting suspension is heated to reflux for 3 days. The mixture is cooled to room temperature, and then filtered. The filtrate is evaporated in vacuo and the residue is purified by silica gel column chromatography (eluent: chloroform) to give 2-acetyl-5-hydroxynaphtho[2,3-b]furan-4,9-dione (0.216 g, 44%) and 2-acetyl-2,3-dihydro-5-hydroxynaphtho[2,3-b]furan-4,9-dione (0.255 g, 51%). This method provides a method for preparing 2-acetyl-5-hydroxynaphtho[2,3-b]furan-4,9-dione at lower cost than Example 6.

Workup

  1. temperaturethe resulting suspension is heated
  2. temperatureto reflux for 3 days
  3. filtrationfiltered
  4. customThe filtrate is evaporated in vacuo
  5. customthe residue is purified by silica gel column chromatography (eluent: chloroform)

Sources & evidence

ORD record
ord-5b289172048a42778cc0b6f5904bab0b
Source dataset
uspto-grants-2011_03
Patent number
US07910752B2

Reaction notes

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