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 (1×), 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 (D2b) as a pale yellow oil (0.270 g, 87%)