Process for preparing alkylidene-substituted -1, 4-dions derivatives

摘要

A process for the preparation of a monoalkylidene substituted 1,4-dions derivatives of formula (Ia) or (Ib) or a mixture of (Ia) and (Ib): wherein: R¹, R² and R³, equal to or different from each other, are hydrogen atoms or C₁-C₂₀ hydrocarbon groups: T¹ and T², equal to or different from each other, are OR⁴, R⁴, NR⁴₂, SR⁴ or PR⁴₂; or T¹ and T² can be fused in an oxygen atom or a NR⁴ group; said process comprises the step of reacting a compound of formula (II) with a compound of formula (IIIa) or (IIIb) in the presence of at least one equivalent with respect to the compound of formula (IIIa) or (IIIb) of a carbonate of metal M or of a compound of formula MT_j such as K₂CO₃ or KHCO₃.