title: Studies toward Australifungin. A Synthesis Dilemma of Regioselective Keto-Enol Tautomerization.
abstract: Studies have advanced a stereocontrolled pathway for the synthesis of australifungin. Elaboration of the trans-fused IMDA product 4 led to the cis-diol 15, which produced the α-hydroxyenone 19 upon oxidation. Computational studies on model systems indicate that the keto-enol tautomer shown for 19 is higher in energy than the keto-enol tautomer represented by the natural product 1. The reactivity of 19 does not permit mild isomerization and subsequent deprotection to yield 1. These findings raise new questions regarding the synthesis and bioactivity of australifungin and related natural products.
authors.affiliation: Department of Chemistry, Indiana University , Bloomington, Indiana 47405, United States.
authors.forename: David R
authors.initials: DR
authors.lastname: Williams
authors.affiliation: Department of Chemistry, Indiana University , Bloomington, Indiana 47405, United States.
authors.forename: J Cullen
authors.initials: JC
authors.lastname: Klein
authors.affiliation: Department of Chemistry, Indiana University , Bloomington, Indiana 47405, United States.
authors.forename: Lucas C
authors.initials: LC
authors.lastname: Kopel
authors.affiliation: Department of Chemistry, University of California , Davis, California 95616, United States.
authors.forename: Nhu
authors.initials: N
authors.lastname: Nguyen
authors.affiliation: Department of Chemistry, University of California , Davis, California 95616, United States.
authors.forename: Dean J
authors.initials: DJ
authors.lastname: Tantillo
mesh_terms: D001203:Ascomycota / Q000737:chemistry; D001688:Biological Products / Q000737:chemistry; D015394:Molecular Structure; D013237:Stereoisomerism; D013764:Tetrahydronaphthalenes / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D001688:Biological Products; D013764:Tetrahydronaphthalenes; C094344:australifungin