Regioselective Synthesis of (Trifluoromethyl)-β-chloroenones.

Abstract The regioselectivity of the conversion of 1,3-diketones into β-chloroenones can be changed by the appropriate choice of the reagent:reaction with “Vilsmeier's reagent” prepared from POCl3, and dimethylformamide or treatment of the diketone with the oxalyl chloride in the presence of dimethylformamide.