5-(Methoxymethoxy)-2,2,4-trimethyl-7-pentyl-2H-1-benzopyran-3-propanoic acid → 5-Hydroxy-2,2,4-trimethyl-7-pentyl-2H-1-benzopyran-3-propanoic acid

HRID 399157Notes

Reaction equation

HRID 399157 reaction equation
COC[O:4][C:5]1[C:10]2[C:11]([CH3:22])=[C:12]([CH2:17][CH2:18][C:19]([OH:21])=[O:20])[C:13]([CH3:16])([CH3:15])[O:14][C:9]=2[CH:8]=[C:7]([CH2:23][CH2:24][CH2:25][CH2:26][CH3:27])[CH:6]=1.C1(C)C=CC(S(O)(=O)=O)=CC=1.[NH+]1C=CC=CC=1>C(O)(C)(C)C>[OH:4][C:5]1[C:10]2[C:11]([CH3:22])=[C:12]([CH2:17][CH2:18][C:19]([OH:21])=[O:20])[C:13]([CH3:16])([CH3:15])[O:14][C:9]=2[CH:8]=[C:7]([CH2:23][CH2:24][CH2:25][CH2:26][CH3:27])[CH:6]=1

Participants

4

Reactant 2

HCID 189701445-(Methoxymethoxy)-2,2,4-trimethyl-7-pentyl-2H-1-benzopyran-3-propanoic acidHCID 22033616Pyridinium.p-toluenesulfonate

Product 1

HCID 189701435-Hydroxy-2,2,4-trimethyl-7-pentyl-2H-1-benzopyran-3-propanoic acid

Reagents, catalysts & solvents 1

HCID 6386tert-ButanolSolvent

Procedure

To a solution of 0.55 g (1.65 mmol) of 5-(Methoxymethoxy)-2,2,4-trimethyl-7-pentyl-2H-1-benzopyran-3-propanoic acid in 60 mL of tert-butyl alcohol (MCB Chem. Co.) under argon was added 4.16 g (10 eq.) of pyridinium para-toluenesulfonic acid (Aldrich) and the reaction mixture boiled under reflux for 1 hr. The reaction mixture was cooled with an ice-water bath and then partitioned between 500 mL of EtOAc and 100 mL of water. The phases were separated and the organic phase washed with water (5×100 mL), half-sat. aq. NaCl (1×100 mL), sat. aq. NaCi (1×100 mL), dried (Na2SO4), evaporated under reduced pressure and the residue dried under high vacuum to give discolored solids. The solids were redissolved and subjected to column chromatography on flash-grade silica gel, eluting with 10% MeOH-CHCl3. The fractions containing product were combined and solvent removed under reduced pressure to give, after drying under high vacuum, 143 mg of 5-Hydroxy-2,2,4-trimethyl-7-pentyl-2H-1-benzopyran-3-propanoic acid as a glass/amorphous solid. HR EI MS: Calc M+, 332.1988; Observed, 332.1985.

Workup

  1. temperatureunder reflux for 1 hr
  2. temperatureThe reaction mixture was cooled with an ice-water bath
  3. custompartitioned between 500 mL of EtOAc and 100 mL of water
  4. customThe phases were separated
  5. washthe organic phase washed with water (5×100 mL), half-sat
  6. dry with materialaq. NaCl (1×100 mL), sat. aq. NaCi (1×100 mL), dried (Na2SO4)
  7. customevaporated under reduced pressure
  8. customthe residue dried under high vacuum
  9. customto give
  10. dissolutionThe solids were redissolved
  11. washeluting with 10% MeOH-CHCl3
  12. additionThe fractions containing product
  13. customsolvent removed under reduced pressure
  14. customto give
  15. dry with materialafter drying under high vacuum, 143 mg of 5-Hydroxy-2,2,4-trimethyl-7-pentyl-2H-1-benzopyran-3-propanoic acid as a glass/amorphous solid

Sources & evidence

ORD record
ord-89dcabf08f3243cf9d1b5ef63c490ffa
Source dataset
uspto-grants-1998_10
Patent number
US05817766

Reaction notes

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