Efficient and scalable protocol for the Z-selective synthesis of unsaturated esters by Horner-Wadsworth-Emmons olefination

The synthesis of a highly Z-selective Horner-Wadsworth-Emmons (HWE) reagent from cheap and readily available starting materials on a 200-g scale is described. The HWE reaction conditions have also been studied in order to design an efficient and scalable protocol leading to Z-selectivities close to 95% with aromatic and aliphatic aldehydes.