title: Synthesis of the isoxazolo[4,3,2-de]phenanthridinone moiety of the parnafungins.
abstract: A practical route to the labile tetracyclic isoxazolo[4,3,2-de]phenanthridinone moiety of the antifungal parnafungins has been developed. Zinc reduction of a methyl 2'-hydroxymethyl-2-nitro-3-biphenylcarboxylate, which was prepared by a Suzuki coupling, afforded a benzisoxazolone that was treated with MsCl and base to generate the labile tetracyclic ring system in 37-47% yield. This compound decomposes to the phenanthridine in CDCl(3) and the phenanthridine N-oxide in aqueous base.
authors.affiliation: Department of Chemistry, MS 015, Brandeis University, Waltham, Massachusetts 02454-9110, USA.
authors.forename: Quan
authors.initials: Q
authors.lastname: Zhou
authors.forename: Barry B
authors.initials: BB
authors.lastname: Snider
mesh_terms: D000935:Antifungal Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D007555:Isoxazoles / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010617:Phenanthridines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D015032:Zinc / Q000737:chemistry
chemical_list: D000935:Antifungal Agents; D007555:Isoxazoles; D010617:Phenanthridines; D015032:Zinc