A new method for the preparation of caffeic acid esters was investigated. Ten caffeic acid esters were prepared by condensation of protocatechualdehyde with malonic acid mono-esters in moderate yield. Malonic acid mono-esters were prepared from the corresponding malonate di-esters. The conformations of compounds are trans (E) form.
AggarwalB.B., GrunbergerD., and BurkeT. R.Jr. WO 9, 809, 620, Sep. 4, 1997.
7.
BankovaV., KujumgievA., IgnatovaA., DyulgerovA., PurebO., ZamjansanJ., and PopovS., Fifth International Conference on Chemistry and Biotechnology of Biologically Active Natural Products, Varna, Bulgaria, Sept. 18-23, 1989, Vol. 2, p 239.
8.
NakanishiK., OltzE. M., and GrunbergerD., US patent 5, 008, 441, 1991.
9.
SonS., LobkowskyE. B., and LewisB. A., Chem. Pharm. Bull., 2001, 49236.
