Propanoic acid, 3-((2-methoxy-2-oxoethyl)thio)-, methyl ester → 2-Thiophenecarboxylic acid, tetrahydro-3-oxo-, methyl ester
Reaktionsgleichung
[Li].[CH3:2][O:3][C:4](=[O:13])[CH2:5][S:6][CH2:7][CH2:8][C:9](OC)=[O:10]>CO>[O:10]=[C:9]1[CH2:8][CH2:7][S:6][CH:5]1[C:4]([O:3][CH3:2])=[O:13]Komponenten
4
Edukt 2
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Versuchsvorschrift
Lithium metal (2.70 g, 390.15 mmol) was added to 500 mL of methanol in an ice-bath. Then at rt methyl 3-(2-methoxy-2-oxoethylthio)propanoate (50.0 g, 260.10 mmol) was added dropwise to the solution. The reaction mixture was stirred overnight. The resulting reaction mixture was evaporated to remove the solvent. The mixture was neutralized to pH=7-8 with 3N HCl and extracted with dichloromethane. The organic layers were combined, washed with brine, dried over anhydrous Na2SO4, filtered and evaporated. The crude residue obtained contained the target as the only isolable product. Purification by column chromatography on silica gel (eluent: PE/EA=20/1-5/1) provided methyl 3-oxo-tetrahydrothiophene-2-carboxylate as a colourless oil (18.0 g, 43%).