p-Toluenesulfonic acid → 2-(2-Buten-1-yl)-8-methoxy-1-tetralone

HRID 264564Notes

Reaction equation

HRID 264564 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[CH:5][CH:6]=[C:7]2[C:12]=1[C:11](=[O:13])[CH2:10][CH2:9][CH2:8]2.[CH3:14][CH:15](O)[CH:16]=[CH2:17].COC(OC)(C)C.C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[CH2:14]([CH:10]1[CH2:9][CH2:8][C:7]2[C:12](=[C:3]([O:2][CH3:1])[CH:4]=[CH:5][CH:6]=2)[C:11]1=[O:13])[CH:15]=[CH:16][CH3:17]

Participants

6

Reactant 4

HCID 6101p-Toluenesulfonic acidHCID 64952,2-DimethoxypropaneHCID 117163-Buten-2-olHCID 112753358-Methoxy-3,4-dihydronaphthalen-1(2H)-one

Product 1

HCID 541248972-(2-Buten-1-yl)-8-methoxy-1-tetraloneYield 22%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

13.7 g of 8-methoxy-1-tetralone were dissolved in 140 ml of toluene under argon and added to 13.3 ml of 3-buten-2-ol, 14.2 ml of 2,2-dimethoxypropane and 300 mg of p-toluenesulfonic acid. The reaction solution was heated to reflux for 90 hours. The solvent was removed in a vacuum and the residue was chromatographed on 500 g of silica gel firstly with hexane/ethyl acetate 9:1, then with hexane/ethyl acetate 4:1 and finally with hexane/ethyl acetate 1:1. In addition to large amounts of unreacted educt (8.3 g) there were obtained 3.95 g (22%) of 2-(2-buten-1-yl)-8-methoxy-1-tetralone as a yellow oil.

Workup

  1. temperatureThe reaction solution was heated
  2. temperatureto reflux for 90 hours
  3. customThe solvent was removed in a vacuum
  4. customthe residue was chromatographed on 500 g of silica gel firstly with hexane/ethyl acetate 9:1
  5. additionIn addition to large amounts of unreacted educt (8.3 g) there

Sources & evidence

ORD record
ord-2e1fc451f6ab48748f84d89860dd7c53
Source dataset
uspto-grants-1997_07
Patent number
US05646173

Reaction notes

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