Synthesis of (E)-alpha,beta-unsaturated amides with high selectivity by using samarium diiodide.
Stereoselective beta-elimination of 2-chloro-3-hydroxyamides 1 is achieved by using samarium diiodide to yield alpha,beta-unsaturated amides 2, in which the C=C bond is di- tri-, or tetrasubstituted. The starting compounds 1 are easily prepared by reaction of the corresponding lithium enolates of alpha-chloroamides with aldehydes or ketones at - 78 degrees C. The influence of the reaction conditions and the structure of the starting compounds on the stereoselectivity of the beta-elimination reaction is also discussed.
Concellón
J M
JM
Departamento de Química Orgánica e Inorgánica, Facultad de Química, Universidad de Oviedo, Spain. jmcg@sauron.quimica.uniovi.es
Pérez-Andrés
J A
JA
Rodríguez-Solla
H
H