p-Toluenesulfonic acid → Methyl 1-(3,4-dihydroxyphenyl)cyclopropanecarboxylate
Reaktionsgleichung
[OH:1][C:2]1[CH:3]=[C:4]([C:9]2([C:12]([OH:14])=[O:13])[CH2:11][CH2:10]2)[CH:5]=[CH:6][C:7]=1[OH:8].[CH3:15]C1C=CC(S(O)(=O)=O)=CC=1>CO>[CH3:15][O:13][C:12]([C:9]1([C:4]2[CH:5]=[CH:6][C:7]([OH:8])=[C:2]([OH:1])[CH:3]=2)[CH2:11][CH2:10]1)=[O:14]Komponenten
4
Edukt 2
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Versuchsvorschrift
To a solution of 1-(3,4-dihydroxyphenyl)cyclopropanecarboxylic acid (4.3 g) in MeOH (30 mL) was added TsOH (0.25 g, 1.3 mmol). The stirring was continued at 50° C. overnight before the mixture was cooled to room temperature. The mixture was concentrated under vacuum and the residue was purified by column chromatography on silica gel (petroleum ether/ethyl acetate 3:1) to give 1-(3,4-dihydroxy-phenyl)-cyclopropanecarboxylic methyl ester (2.1 g). 1H NMR (DMSO 300 MHz) δ 8.81 (bra, 2H), 6.66 (d, J=2.1 Hz, 1H), 6.61 (d, J=8.1 Hz, 1H), 6.53 (dd, J=2.1, 8.1 Hz, 1H), 3.51 (s, 3H), 1.38-1.35 (m, 2H), 1.07-1.03 (m, 2H).