p-Toluenesulfonic acid → HCID 23291432, compound
Reaction equation
[S:1]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][C:9]=2[C:11]([O:13][CH3:14])=[O:12])[CH:4](O)[CH2:3][CH2:2]1.C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[CH3:14][O:13][C:11]([C:9]1[CH:8]=[CH:7][CH:6]=[C:5]2[C:10]=1[S:1][CH2:2][CH:3]=[CH:4]2)=[O:12]Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
Methyl thiochroman-4-ol-8-carboxylate (0.337 g, 1.50 mmol) was dissolved in toluene (25 ml) and was treated with p-toluenesulphonic acid (0.028 g, 0.15 mmol). The mixture was then heated to reflux with stirring. After 2 h, the reaction mixture was allowed to cool and was washed with sodium hydrogen carbonate solution. The aqueous layer was then extracted with EtOAc (1x), and the combined organic layers were dried (Na2SO4) and evaporated under reduced pressure to give a pale yellow oil which was purified by silica-gel chromatography (pentane: Et2O 2:1 as eluant) to give the title compound as a pale yellow oil (0.270 g, 87%)