Synthesis of (E)-alpha-hydroxy-beta,gamma-unsaturated amides with high selectivity from alpha,beta-epoxyamides by using catalytic samarium diiodide or triiodide.
The highly stereoselective synthesis of (E)-alpha-hydroxy-beta,gamma-unsaturated amides starting from alpha,beta-epoxyamides, by using catalytic SmI2 or SmI3, was achieved. This transformation can also be carried out by using SmI2 generated in situ from samarium powder and diiodomethane. The starting compounds 1 are easily prepared by the reaction of enolates derived from alpha-chloroamides with ketones at -78 degrees C. A mechanism to explain this transformation has been proposed. Cyclopropanation of (E)-alpha-hydroxy-beta,gamma-unsaturated amides has been performed to demonstrate their synthetic applications.
Concellón
José M
JM
Departamento de Química Orgánica e Inorgánica, Facultad de Química, Universidad de Oviedo, E-33071 Oviedo, Spain. jmcg@sauron.quimica.uniovi.es
Bernad
Pablo L
PL
Bardales
Eva
E
D000577:Amides / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D004852:Epoxy Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D007454:Iodides / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D015394:Molecular Structure; D012493:Samarium / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D013237:Stereoisomerism
D000577:Amides; D004852:Epoxy Compounds; D007454:Iodides; D012493:Samarium; C409809:samarium diiodide