Abstract: In this paper, the reaction of 1, 2, 3-trisubstituted electron-deficient cyclopropane derivatives ets-1-benzoyl-2-p-substituted phenyl-6, 6-dimethyl-5, 7-dioxo-spiro-[2,5]-4, 8-octadiones with methanol was studied. The structures of the reaction products were confirmed as methyl　β-benzoyl-γ-methoxy-γ-p- substituted phenylbutyrates by means of IR, MS, microanalysis, ¹H, ¹³C NMRspectroscopies and APTtechniques. The reaction mechanism for the formation of the product was also proposed.

Key words: 1, 2, 3-Trisubstituted cyclopropane, Methanolysis, Methyl butyrate