Carbon Dioxide → 5-Oxo-5,6,7,8-tetrahydronaphthalene-2-carboxylic acid

HRID 1601467Notes

Reaction equation

HRID 1601467 reaction equation
C1O[C:4]2([CH2:13][CH2:12][C:11]3[C:6](=[CH:7][CH:8]=[C:9](Br)[CH:10]=3)[CH2:5]2)OC1.C([Li])(C)(C)C.[C:21](=[O:23])=[O:22].C1C[O:27]CC1>>[C:5]1(=[O:27])[C:6]2[C:11](=[CH:10][C:9]([C:21]([OH:23])=[O:22])=[CH:8][CH:7]=2)[CH2:12][CH2:13][CH2:4]1

Participants

5

Reactant 4

HCID 280Carbon DioxideHCID 8028TetrahydrofuranHCID 233778946-Bromo-2-tetralone ethylene ketalHCID 178418306HCID 178418306, compound

Product 1

HCID 28184935-Oxo-5,6,7,8-tetrahydronaphthalene-2-carboxylic acid

Conditions

Temperature
-78 °C

Procedure

6-Bromo-2-tetralone ethylene ketal (2.2 g, 8.15 mmol) was dissolved in anhydrous THF (30 mL), cooled to -78° C. and treated with tert-butyllithium (12.05 mL, 20.4 mmol, 1.7M in pentane) under an atmosphere of nitrogen. After stirring for 30 minutes, anhydrous carbon dioxide gas was passed through the reaction mixture for 20 minutes at -78° C. The suspension was then allowed to warm to ambient temperature. The solution was quenched with water and acidified with 1N HCl, then extracted 2×EtOAc. The organic extracts were washed with brine, dried over Na2SO4 and concentrated in vacuo to a pale brown oil. The oily residue was applied to a silica flash chromatography column and eluted with 30%-50% EtOAc in hexanes to yield tetralone-6-carboxylic acid, ethylene ketal 1.06 g (55%) of a slowly crystallizing solid. NMR. MS.

Workup

  1. temperatureto warm to ambient temperature
  2. customThe solution was quenched with water
  3. extractionextracted 2×EtOAc
  4. washThe organic extracts were washed with brine
  5. dry with materialdried over Na2SO4
  6. concentrationconcentrated in vacuo to a pale brown oil
  7. washeluted with 30%-50% EtOAc in hexanes

Sources & evidence

ORD record
ord-78a14e30fb1849368d81ad0ba94c09e6
Source dataset
uspto-grants-1999_11
Patent number
US05977154

Reaction notes

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