title: Ring Transformation of Glycidic Amides with Ortho-Metalated Phenols to Enantiopure 3-Hydroxychromanones.
abstract: A novel access to hitherto unknown enantiopure 2-alkylchroman-4-ones 10 was found by a reaction of ortho-metalated O-MOM-protected phenols with Weinreb amides 8 of enantiopure cis- or trans-glycidic acids. Upon acidic hydrolysis, the resulting o-MOMO-benzoyloxiranes 9 undergo ring transformation to 2-alkylchroman-4-ones 10. 2-Alkylidenecoumaran-3-ones 11 were formed as alternative products, depending on the configuration of the starting oxirane ring and on the type of phenol used as starting material.
authors.affiliation: Institut für Chemie, Humboldt-Universität Berlin, Hessische Strasse 1-2, D-10115 Berlin, Germany.
authors.forename: Karsten
authors.initials: K
authors.lastname: Woydowski
authors.forename: Burkhard
authors.initials: B
authors.lastname: Ziemer
authors.forename: Jürgen
authors.initials: J
authors.lastname: Liebscher