title: Synthesis of the bis-potassium salts of 5-hydroxy-3-oxopent-4-enoic acids and their use for the efficient preparation of 4-hydroxy-2H-pyran-2-ones and other heterocycles.
abstract: 5-Hydroxy-3-oxopent-4-enoic acid esters can be efficiently transformed into the stable bis-potassium salts of the corresponding 5-hydroxy-3-oxopent-4-enoic acids, from which the sensitive acids are released in situ, the latter being converted into substituted 4-hydroxy-2H-pyran-2-ones, pyrazoles and isoxazoles under mild conditions; the efficiency of this method is demonstrated by the first synthesis of two naturally occurring pyrones.
authors.affiliation: Bioorganische Chemie, Institut für Chemie, Universität Hohenheim, Garbenstrasse 30, D-70599 Stuttgart, Germany.
authors.forename: Dietmar
authors.initials: D
authors.lastname: Schmidt
authors.forename: Jürgen
authors.initials: J
authors.lastname: Conrad
authors.forename: Iris
authors.initials: I
authors.lastname: Klaiber
authors.forename: Uwe
authors.initials: U
authors.lastname: Beifuss
mesh_terms: D000143:Acids / Q000737:chemistry*; D000737:Androstenols / Q000138:chemical synthesis / Q000737:chemistry; D006900:Hydroxylation; D015394:Molecular Structure; D017680:Potassium Compounds / Q000138:chemical synthesis*; D011720:Pyrazoles / Q000138:chemical synthesis / Q000737:chemistry
chemical_list: D000143:Acids; D000737:Androstenols; D017680:Potassium Compounds; D011720:Pyrazoles; C017039:azastene