New and Facile Approach for the Synthesis of (E)‐α,β‐Unsaturated Esters and Ketones

A general and practical synthesis of (E)-α,β-unsaturated esters and ketones was achieved by the reaction of carbonyl compounds with ethyl-4,4,4-trifluoroacetoacetate and trifluoro-substituted 1,3-diketones in the presence of piperidine in dichloromethane at room temperature (≈40 °C) with excellent stereoselectivity (see scheme).