title: Synthetic studies on perophoramidine and the communesins: construction of the vicinal quaternary stereocenters.
abstract: An efficient synthetic strategy for installation of the two vicinal quaternary carbon centers of the communesins is reported. Key steps include the O-allylation/Claisen rearrangement of spirolactone systems, which are formed by tandem intramolecular Heck cyclization/carbonylation. Substituent and solvent effects on the stereochemical outcome of the Claisen rearrangements have been examined. The stereochemical assignment of the allyl spirolactone previously reported as 17 has now been revised to 31, which has the communesin relative configuration at the quaternary carbons. Key C-allyl spirolactone 59 bearing functional handles required for the communesin core has been constructed with a 9.8:1 diastereomer ratio.
authors.affiliation: Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
authors.forename: Jae Hong
authors.initials: JH
authors.lastname: Seo
authors.forename: Gerald D
authors.initials: GD
authors.lastname: Artman
authors.forename: Steven M
authors.initials: SM
authors.lastname: Weinreb
mesh_terms: D006576:Heterocyclic Compounds, 4 or More Rings / Q000138:chemical synthesis* / Q000737:chemistry; D006846:Hydrocarbons, Halogenated / Q000138:chemical synthesis* / Q000737:chemistry; D008968:Molecular Conformation; D013237:Stereoisomerism
chemical_list: D006576:Heterocyclic Compounds, 4 or More Rings; D006846:Hydrocarbons, Halogenated; C522026:communesin A; C483283:communesin B; C483284:communesin C; C483285:communesin D; C493628:communesin E; C522025:communesin F; C499269:communesin G; C472225:perophoramidine