p-Toluenesulfonic acid → 2-Methyl-3H-cyclopenta[a]naphthalene
Reaction equation
[CH3:1][CH:2]1[CH:14](O)[C:5]2=[C:6]3[C:11](=[CH:12][CH:13]=[C:4]2[CH2:3]1)[CH:10]=[CH:9][CH:8]=[CH:7]3.C1(C)C=CC(S(O)(=O)=O)=CC=1.C([O-])([O-])=O.[Na+].[Na+]>C1C=CC=CC=1>[CH3:1][C:2]1[CH2:3][C:4]2[C:5]([CH:14]=1)=[C:6]1[C:11](=[CH:12][CH:13]=2)[CH:10]=[CH:9][CH:8]=[CH:7]1Participants
5
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Procedure
A mixture of 2-methyl-2,3-dihydro-1H-cyclopenta[a]naphthalen-1-ol (obtained as described above) and 1 g of p-toluenesulphonic acid in 200 mL of benzene was refluxed for 1 h. Then the reaction mixture was cooled to room temperature and treated with a saturated aqueous solution of Na2CO3. The organic phase was isolated, dried over MgSO4 and evaporated off to dryness. Yield 14.2 g (55% based on starting 2-methyl-2,3-dihydro-1H-cyclopenta[a]naphtalen-1-one).