p-Toluenesulfonic acid → 2,2,4,5-Tetramethyl-4-hexen-3-one
Reaction equation
[CH3:1][C:2]([CH3:11])([C:4](=[O:10])[CH:5]([CH3:9])[C:6]([CH3:8])=[CH2:7])[CH3:3].C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[CH3:3][C:2]([CH3:11])([C:4](=[O:10])[C:5]([CH3:9])=[C:6]([CH3:8])[CH3:7])[CH3:1]Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
30.8 g (0.2 mole) of 2,2,4,5-tetramethyl-5-hexen-3-one were heated to 100° in 100 ml of toluene in the presence of 3.08 g of p-toluenesulfonic acid. After 24 h, the mixture was cooled down and extracted with ether. After neutralizing with an aqueous solution saturated with NaHCO3, the organic phase was washed with water, then with a solution saturated with NaCl, and dried with Na2SO4. Evaporation and distillation of the residue, followed by fractional distillation, provided a fraction having B.p. 60°/1.06×103Pa NMR(1H, 360MHz): 1.18(s, 9H); 1.57(s, 3H); 1.66(s, 3H); 1.77(s, 3H) δppm MS:m/z:154(3, M+), 97(100), 69(62), 41(65), 39(20).