title: Synthesis and determination of absolute configuration of α-pyrones isolated from Penicillium corylophilum.
abstract: The first total synthesis of (S)-6-(2,9-dihydroxynonyl)-4-hydroxy-3-methyl-2H-pyran-2-one, 4-hydroxy-3-methyl-6-((2S,4R)-2,4,11-trihydroxyundecyl)-2H-pyran-2-one, and its unnatural 2R,4R-isomer starting from commercially available 1,8-octanediol is described. The synthesis led to the revision of the proposed structural assignment of the natural product as (R)-6-(2,9-dihydroxynonyl)-4-hydroxy-3-methyl-2H-pyran-2-one. The key steps include chiral auxiliary mediated asymmetric acetate aldol reaction, dianion addition, and base mediated cyclization to form an α-pyrone ring.
authors.affiliation: Academy of Scientific and Innovative Research, ‡Division of Natural Products Chemistry, CSIR-Indian Institute of Chemical Technology , Hyderabad-500007, India.
authors.forename: J S
authors.initials: JS
authors.lastname: Yadav
authors.forename: B
authors.initials: B
authors.lastname: Ganganna
authors.forename: Palash
authors.initials: P
authors.lastname: Dutta
authors.forename: Kiran K
authors.initials: KK
authors.lastname: Singarapu
mesh_terms: D000447:Aldehydes / Q000737:chemistry; D001688:Biological Products / Q000737:chemistry*; D003500:Cyclization; D015394:Molecular Structure; D010407:Penicillium / Q000737:chemistry*; D011753:Pyrones / Q000138:chemical synthesis* / Q000737:chemistry / Q000302:isolation & purification; D013237:Stereoisomerism
chemical_list: C000599342:4-hydroxy-3-methyl-6-((2S,4R)-2,4,11-trihydroxyundecyl)-2H-pyran-2-one; C000599341:6-(2,9-dihydroxynonyl)-4-hydroxy-3-methyl-2H-pyran-2-one; D000447:Aldehydes; D001688:Biological Products; D011753:Pyrones; C116609:3-hydroxybutanal