Hydrochloric Acid → 5,7-Dihydroxyspiro[chroman-2,1'-cyclobutan]-4-one

HRID 1516711Notes

Reaction equation

HRID 1516711 reaction equation
O.O.[OH:3][C:4]1[CH:9]=[C:8]([OH:10])[CH:7]=[C:6]([OH:11])[CH:5]=1.[C:12]1(=[CH:16][C:17](O)=[O:18])[CH2:15][CH2:14][CH2:13]1.Cl>>[OH:3][C:4]1[CH:9]=[C:8]([OH:10])[CH:7]=[C:6]2[C:5]=1[C:17](=[O:18])[CH2:16][C:12]1([O:11]2)[CH2:15][CH2:14][CH2:13]1

Participants

4

Reactant 3

HCID 313Hydrochloric AcidHCID 80196Phloroglucinol dihydrateHCID 219231732-Cyclobutylideneacetic acid

Product 1

HCID 580030505,7-Dihydroxyspiro[chroman-2,1'-cyclobutan]-4-one

Conditions

Temperature
70 °C

Procedure

8 g (49.34 mmol) of 1,3,5-trihydroxybenzene dihydrate and 6.64 g (59.21 mmol) of cyclo-butylideneacetic acid (Example 40A) are initially charged, 25 ml (197.4 mmol) of boron trifluoride/diethyl ether complex are added and the mixture is then heated to 70° C. After three hours, the mixture is cooled, poured into 600 ml of ice-water, acidified with 6 N hydrochloric acid and extracted repeatedly with ethyl acetate. The combined organic phases are washed twice with saturated sodium chloride solution, dried over sodium sulfate, filtered and concentrated. The crude product is taken up in dichloromethane and stirred, and insoluble solid is then filtered off. Silica gel is added to the filtrate, the mixture is concentrated and the residue is purified chromatographically on silica gel (mobile phase: cyclohexane→cyclohexane/ethyl acetate 5:1). This gives 4.7 g (43% of theory) of the title compound.

Workup

  1. addition25 ml (197.4 mmol) of boron trifluoride/diethyl ether complex are added
  2. temperaturethe mixture is cooled
  3. extractionextracted repeatedly with ethyl acetate
  4. washThe combined organic phases are washed twice with saturated sodium chloride solution
  5. dry with materialdried over sodium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated
  8. filtrationinsoluble solid is then filtered off
  9. additionSilica gel is added to the filtrate
  10. concentrationthe mixture is concentrated
  11. customthe residue is purified chromatographically on silica gel (mobile phase: cyclohexane→cyclohexane/ethyl acetate 5:1)

Sources & evidence

ORD record
ord-3d9ed3398fa64d24bf83f31fd735942e
Source dataset
uspto-grants-2012_07
Patent number
US08227511B2

Reaction notes

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