Commercially available zinc perchlorate hexahydrate [Zn(ClO_4)_2.6H_2O] was found to be a highly effective catalyst for the transesterification of malonic esters with alcohols. The treatment of methyl-, ethyl-, or \alpha-substituted malonic esters with primary or secondary alcohols in the presence of a catalytic amount of zinc perchlorate results in good to high yields of the corresponding esters (68%-99%). Mono-transesterification products are also obtained in moderate to good yields (22%-42%). The reaction was also carried out with 2-mono- and di-substituted malonic esters, and in the case of 2-mono- and di-substituted malonic esters, the reaction time is, in some cases, shorter, in which the yields are comparable with unsubstituted derivatives. The cyanomethyl and bis-cyanomethyl malonic ester derivatives are also used for transesterification and the corresponding products are obtained in high yields. No reaction occurs with the CN group during the reaction.
Transesterification, zinc perchlorate, malonic esters, mono-substituted malonic esters, unsymmetrical malonic esters
TURAL, SERVET (2008) "Zinc Perchlorate Hexahydrate Catalyzed Mono- and Bis-Transesterification of Malonic Esters," Turkish Journal of Chemistry: Vol. 32: No. 2, Article 4. Available at: https://journals.tubitak.gov.tr/chem/vol32/iss2/4