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.

SUBMITTER: Zhou Q 

PROVIDER: S-EPMC2760249 | biostudies-literature | 2009 Jul

REPOSITORIES: biostudies-literature