title: Total regioselective and diastereospecific iodolysis of 2,3-epoxyamides promoted by SmI2: synthesis of (2R*,3R*)- or (2R,3S)-2-hydroxy-3-iodoamides.
abstract: The use of samarium diiodide as a source of iodides is reported. Thus, 2-hydroxy-3-iodoamides were obtained, with total regioselectivity, by treatment of 2,3-epoxyamides, in which the oxirane ring is 2,3-disubstituted or 2,2,3-trisubstituted, with SmI2. The ring-opening reaction was diastereospecific and (2R*,3R*)- or (2R*,3S*)-2-hydroxy-3-iodoamides were obtained from cis- or trans-epoxyamides, respectively. The relative configuration of 2-hydroxy-3-iodoamides was established by X-ray analysis. A mechanism to explain this transformation has been proposed. The starting compounds 1 are easily prepared by the reaction of enolates derived from 2-chloroamides with aldehydes at -78 degrees C.
authors.affiliation: Departamento de Química Orgánica e Inorgánica, Facultad de Química, Universidad de Oviedo, Julián Clavería, 8, 33071 Oviedo, Spain. jmcg@fq.uniovi.es
authors.forename: José M
authors.initials: JM
authors.lastname: Concellón
authors.forename: Eva
authors.initials: E
authors.lastname: Bardales
authors.forename: Carmen
authors.initials: C
authors.lastname: Concellón
authors.forename: Santiago
authors.initials: S
authors.lastname: García-Granda
authors.forename: M Rosario
authors.initials: MR
authors.lastname: Díaz