Horner-Wadsworth-Emmons Reaction

The Horner-Wadsworth-Emmons reaction (HWE) is a frequently used synthetic method to obtain substituted (di- and tri-) olefin products from aldehydes and ketones. E-olefins are generally preferred over Z products, and selectivity can be adjusted by modifying conditions. Phosphonate esters are typically reacted with strong bases, and produce reactive and stabilized phosphonium anions, which readily react with aldehydes and ketones. The given phosphonate byproducts are easily removed by extraction.