HCID 18970134, compound → rac-3,4-Dihydro-5-hydroxy-2,2,4-trimethyl-7-pentyl-2H-1-benzopyran-3-propanol

HRID 399160Notes

Reaction equation

HRID 399160 reaction equation
[CH2:1]([C:6]1[CH:7]=[C:8]([OH:23])[C:9]([CH:13]([CH:15]2[CH2:20][CH2:19][CH2:18][O:17][C:16]2([CH3:22])[CH3:21])[CH3:14])=[C:10]([OH:12])[CH:11]=1)[CH2:2][CH2:3][CH2:4][CH3:5].C1(C)C=CC(S(O)(=O)=O)=CC=1.[NH+]1C=CC=CC=1>C1(C)C=CC=CC=1.CCOC(C)=O>[OH:12][C:10]1[C:9]2[CH:13]([CH3:14])[CH:15]([CH2:20][CH2:19][CH2:18][OH:17])[C:16]([CH3:21])([CH3:22])[O:23][C:8]=2[CH:7]=[C:6]([CH2:1][CH2:2][CH2:3][CH2:4][CH3:5])[CH:11]=1

Participants

5

Reactant 2

HCID 18970134HCID 18970134, compoundHCID 22033616Pyridinium.p-toluenesulfonate

Product 1

HCID 18970139rac-3,4-Dihydro-5-hydroxy-2,2,4-trimethyl-7-pentyl-2H-1-benzopyran-3-propanolYield 36.2%

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 8857Ethyl AcetateSolvent

Procedure

A solution of 9.4 g of 5-Pentyl-2-[1-(tetrahydro-2,2-dimethyl-2H-pyran-3-yl)ethyl]-1,3-benzenediol in 400 mL of toluene containing a catalytic amount of pyridinium para-toluenesulfonic acid (Aldrich) was heated to 60° C. under argon for 2 hr. The reaction was cooled to RT, diluted with EtOAc, washed with 0.1N aq. HCl (×2), water (×2), sat. aq. NaHCO3, dried and evaporated under reduced pressure. The material obtained was purified by extensive chromatography to give 3.4 g (35%) of rac-3,4-Dihydro-5-hydroxy-2,2,4-trimethyl-7-pentyl-2H-1-benzopyran-3-propanol as a pale yellow amorphous solid. HR EI MS: Calc M+, 320.2351; Observed, 320.2377. Ratio of 3:1 diastereoisomers as shown by 1 H-NMR.

Workup

  1. washwashed with 0.1N aq. HCl (×2), water (×2), sat. aq. NaHCO3
  2. customdried
  3. customevaporated under reduced pressure
  4. customThe material obtained
  5. customwas purified by extensive chromatography

Sources & evidence

ORD record
ord-c458c528bea24e0ba168b6ae8f20fe3e
Source dataset
uspto-grants-1998_10
Patent number
US05817766

Reaction notes

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