title: Asymmetric total syntheses of (-)-penicipyrone and (-)-tenuipyrone via biomimetic cascade intermolecular Michael addition/cycloketalization.
abstract: The first total syntheses of (-)-penicipyrone and (-)-tenuipyrone were accomplished enantioselectively in 12 steps with an 11% yield and 6 steps with a 28% yield from the known 4-((tert-butyldimethylsilyl)oxy)-cyclopent-2-enone, respectively, by developing a biomimetic bimolecular cascade cyclization featuring an intermolecular Michael addition/cyclo-(spiro-)ketalization sequence. The relative, absolute stereochemistry and carbon connectivity of penicipyrone was further confirmed by X-ray crystallographic analysis and comparison of optical rotations.
authors.affiliation: Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
authors.forename: Liyan
authors.initials: L
authors.lastname: Song
authors.forename: Hongliang
authors.initials: H
authors.lastname: Yao
authors.forename: Liangyu
authors.initials: L
authors.lastname: Zhu
authors.forename: Rongbiao
authors.initials: R
authors.lastname: Tong
mesh_terms: D002384:Catalysis; D018360:Crystallography, X-Ray; D003500:Cyclization; D006999:Hypocreales / Q000737:chemistry; D007783:Lactones / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D010407:Penicillium / Q000737:chemistry; D011753:Pyrones / Q000138:chemical synthesis* / Q000737:chemistry; D013141:Spiro Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D007783:Lactones; D011753:Pyrones; D013141:Spiro Compounds; C545749:penicipyrone; C571399:tenuipyrone