Ethyl crotonate was chosen as the α, β-unsaturated carboxylic acid ester, and the Grignard reaction of 2-bromothiophene and the ester was carried out. In either 1:1 or 1:2 molar ratio, the product was 2-(1′-thienyl)-propylthienone-1′, and the unsaturated ketone (I) and saturated ester (II), the intermediates of the reaction, could not be obtained.
