Synthetic studies on perophoramidine and the communesins: construction of the vicinal quaternary stereocenters.
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.
Seo
Jae Hong
JH
Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
Artman
Gerald D
GD
Weinreb
Steven M
SM
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
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