Ethyl α‐Nitrocinnamates in the Synthesis of Highly Functionalized Isoxazoles

An effective method for the synthesis of highly functionalized isoxazoles from readily available starting ethyl α‐nitrocinnamates has been developed. Ethyl α‐nitrocinnamates react smoothly with α‐nitro carbonyl compounds to produceisoxazoles in good yields. Michael addition of pyridinium ylides to ethyl α‐nitrocinnamates can also produce these isoxazoles effectively. These pyridinium salts can be generated in situ from the corresponding alkyl bromides. The one‐pot multicomponent process was also developed. Isoxazoles can be produced directly from readily available aromatic aldehydes, ethyl nitroacetate, and pyridinium salts.