Reaction #1093486

Reaction equation

Na2SO3

EtOAc

(−)-Isopulegol

OXONE

→

(1R, 2R, 5R)-2-Acetyl-5-methyl cyclohexanol

Yield 34.0%

Solvents

DMF

Conditions

Workup

1. 1
   workup.STIRRINGThe reaction was stirred at room temperature for 3 hours or until the solution
2. 2
   Otherthe completion of the reaction which
3. 3
   workup.STIRRINGstirred for an additional hour or until solution
4. 4
   Extractionto extract the products and 1N HCl
5. 5
   workup.DISSOLUTIONto dissolve the salts
6. 6
   ExtractionThe organic extract
7. 7
   Washwas washed with 1N HCl (50 mL×3) and brine (50 mL)
8. 8
   Dryingdried over Na2SO4
9. 9
   Otherthe solvent was removed under reduced pressure
10. 10
    Otherto obtain the crude product

Procedure

(−)-Isopulegol (60 mg) was dissolved in DMF (4 mL), and OsO4 (0.05 mL, 2.5% in tBuOH) was added and stirred for 5 min. OXONE (0.235 g) was added in one portion and the reaction had a final volume (6 mL). The reaction was stirred at room temperature for 3 hours or until the solution becomes colorless. This usually marks the completion of the reaction which was verified by TLC or GC. Na2SO3 (360 mg) was added, to reduce the remaining Os(VIII), and stirred for an additional hour or until solution became dark brown/black. EtOAc was added to extract the products and 1N HCl was used to dissolve the salts. The organic extract was washed with 1N HCl (50 mL×3) and brine (50 mL), dried over Na2SO4, and the solvent was removed under reduced pressure to obtain the crude product. (1R, 2R, 5R)-2-Acetyl-5-methyl cyclohexanol and (1R, 2R, 5R)-2-Acetyl-5-methyl cyclohexanyl formate were obtained in 44% and 34% yield respectively after purification by silica gel column chromatography.

Source