Mechanism of Michael addition of ethyl acetoacetate to chalcone catalyzed by activated Ba(OH)2

Preliminary studies of the mechanism of Michael addition of ethyl acetoacetate to chalcone are presented. Different products may be obtained with good yields (≧80%) and selectivities (≃100%), under different reaction conditions. A mechanism based on the geometric characteristics of the active site of activated barium hydroxide (C-200) is proposed.