title: Enantiocontrolled synthesis of a tetracyclic aminal corresponding to the core subunit of diazonamide A.
abstract: A chiral benzylic ether serves as an auxiliary for oxindole carboxylation (dr 5.2:1.0) that sets C10 configuration in a potential diazonamide precursor. The chiral substituent allows diastereomer separation and departs during a subsequent acid-catalyzed ring closure to form a tetracyclic aminal. With suitable N-protection, crystallization affords the aminal with 98-99% ee.
authors.affiliation: Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States.
authors.forename: Gorka
authors.initials: G
authors.lastname: Peris
authors.affiliation: Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States.
authors.forename: Edwin
authors.initials: E
authors.lastname: Vedejs
mesh_terms: D006576:Heterocyclic Compounds, 4 or More Rings / Q000138:chemical synthesis* / Q000737:chemistry; D008968:Molecular Conformation; D010080:Oxazoles / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D006576:Heterocyclic Compounds, 4 or More Rings; D010080:Oxazoles; C408862:diazonamide A