p-Toluenesulfonic acid → HCID 9794426, compound

HRID 1934862Notes

Reaction equation

HRID 1934862 reaction equation
[C:1]([O:9][C:10]12[O:16][CH:11]1[CH2:12][CH2:13][CH2:14][CH2:15]2)(=[O:8])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.CC1C=CC(S(O)(=O)=O)=CC=1>C(Cl)Cl.CCOCC.CC(O[Ti](OC(C)C)(OC(C)C)OC(C)C)C>[C:1]([O:9][C@@H:10]1[CH2:15][CH2:14][CH2:13][CH2:12][C:11]1=[O:16])(=[O:8])[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

6

Reactant 2

HCID 6101p-Toluenesulfonic acidHCID 14416934HCID 14416934, compound

Product 1

HCID 9794426HCID 9794426, compoundYield 78%

Reagents, catalysts & solvents 3

HCID 178460666HCID 178460666, compoundCatalystHCID 3283Diethyl EtherSolventHCID 6344DichloromethaneSolvent2×

Procedure

To a solution of (R)-(+)-binaphthol (7.9 mg, 0.0275 mmol) in CH2Cl2 (0.5 mL) was added a solution of Ti(OiPr)4 (3.8 uL, 3.6 mg, 0.0125 mmol) in CH2Cl2 (0.5 mL). Upon stirring at room temperature for 5-10 h, the reaction mixture was concentrated and dried using a vacuum pump (ca. 0.5 h). The catalyst was then dissolved in Et2O (1 mL) and cooled in an ice bath. To this solution was added a solution of racemic 1-benzoyloxy-1,2-epoxycyclohexane (0.109 g, 0.5 mmol) in Et2O (1 mL). After stirring at 0° C. for 1 h, the reaction mixture was quenched with saturated NaHCO3 solution (4 mL) and poured into a mixture of ether (20 mL) and saturated NaHCO3 solution (10 mL). The organic layer was washed with water and brine, dried (Na2SO4), and rapidly filtered through a plug of silica gel (ca. 10 g) (pre-treated with 5% Et3N in hexane and washed thoroughly with hexane to remove Et3N before use). The silica gel was further washed with Et2O (10 mL). The combined ether solutions were concentrated to give a residue. Upon drying under vacuum for 1 h, the mixture was dissolved in CH2Cl2 (4 mL) followed by addition of anhydrous p-TsOH (8.6 mg, 0.05 mmol). After stirring at room temperature for 20 min, the mixture was rapidly filtered through a plug of silica gel (ca. 10 g) (without Et3N treatment) followed by washing with ether (2×10 mL). The combined solutions were concentrated to give (R)-2-benzoyloxycyclohexanone as a white solid (0.0845 g, 78% yield, 93% ee).

Workup

  1. concentrationthe reaction mixture was concentrated
  2. customdried
  3. customa vacuum pump (ca. 0.5 h)
  4. dissolutionThe catalyst was then dissolved in Et2O (1 mL)
  5. temperaturecooled in an ice bath
  6. stirringAfter stirring at 0° C. for 1 h
  7. customthe reaction mixture was quenched with saturated NaHCO3 solution (4 mL)
  8. additionpoured into a mixture of ether (20 mL) and saturated NaHCO3 solution (10 mL)
  9. washThe organic layer was washed with water and brine
  10. dry with materialdried (Na2SO4)
  11. filtrationrapidly filtered through a plug of silica gel (ca. 10 g) (
  12. additionpre-treated with 5% Et3N in hexane
  13. washwashed thoroughly with hexane
  14. customto remove Et3N before use)
  15. washThe silica gel was further washed with Et2O (10 mL)
  16. concentrationThe combined ether solutions were concentrated
  17. customto give a residue
  18. customUpon drying under vacuum for 1 h
  19. dissolutionthe mixture was dissolved in CH2Cl2 (4 mL)
  20. stirringAfter stirring at room temperature for 20 min
  21. filtrationthe mixture was rapidly filtered through a plug of silica gel (ca. 10 g) (without Et3N treatment)
  22. washby washing with ether (2×10 mL)
  23. concentrationThe combined solutions were concentrated

Sources & evidence

ORD record
ord-bc51e8fe3c614e8a8ce4ecc1efde86f4
Source dataset
uspto-grants-2002_05
Patent number
US06384265B1

Reaction notes

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