Sulfuric Acid → (1R,2R,5S)-2,6,6-trimethylbicyclo[3.1.1]heptan-3-one

HRID 2404598Notes

Reaction equation

HRID 2404598 reaction equation
OS(O)(=O)=O.CC(C)=O.OS(O)(=O)=O.O=[Cr](=O)=O.[CH3:19][C@H:20]1[C@H:25]([OH:26])[CH2:24][C@@H:23]2[CH2:27][C@H:21]1[C:22]2([CH3:29])[CH3:28]>O.CC(C)=O>[CH3:19][C@H:20]1[C:25](=[O:26])[CH2:24][C@@H:23]2[CH2:27][C@H:21]1[C:22]2([CH3:28])[CH3:29]

Participants

6

Reactant 3

HCID 1118Sulfuric AcidHCID 10524983(-)-IsopinocampheolHCID 131709961Jones' reagent

Product 1

HCID 10329459(1R,2R,5S)-2,6,6-trimethylbicyclo[3.1.1]heptan-3-oneYield 93.4%

Reagents, catalysts & solvents 2

HCID 180AcetoneSolventHCID 962WaterSolvent3×

Procedure

add a mixture of 9 ml of H2SO4 and 40 ml of H2O to a solution of Cr2O3 (15.0 g, 0.15 mol) in H2O (20 mL) at 0° C. Add dropwise the above Jones reagent to a solution of (1R,2R,3R,5S)-2,6,6-trimethylbicyclo[3.1.1]heptan-3-ol (23.1 g, 0.15 mol) in acetone (100 mL) over a period for 2 hours at 0° C. Stir the resultant mixture for additional 1 hour. Dilute the mixture with 100 mL of water and then extract the aqueous mixture with ether (50 mL×3). The combined organic layers are washed with brine (20 mL), dried over Na2SO4, filtered, and concentrated under vacuum to give crude (1R,2R,5S)-2,6,6-trimethylbicyclo[3.1.1]heptan-3-one as pale yellow oil (21.3 g, yield: 93.4%), MS (m/z): 151 (M−1).

Workup

  1. additionadd
  2. extractionextract the aqueous mixture with ether (50 mL×3)
  3. washThe combined organic layers are washed with brine (20 mL)
  4. dry with materialdried over Na2SO4
  5. filtrationfiltered
  6. concentrationconcentrated under vacuum

Sources & evidence

ORD record
ord-d75c3bc66bdd4406905bd0313949618d
Source dataset
uspto-grants-2014_08
Patent number
US08802728B2

Reaction notes

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