title: 9-Membered carbocycle formation: development of distinct Friedel-Crafts cyclizations and application to a scalable total synthesis of (±)-caraphenol A.
abstract: Explorations into a series of different approaches for 9-membered carbocycle formation have afforded the first reported example of a 9-exo-dig ring closure via a Au(III)-promoted reaction between an alkyne and an aryl ring as well as several additional, unique Friedel-Crafts-type cyclizations. Analyses of the factors leading to the success of these transformations are provided, with the application of one of the developed 9-membered ring closures affording an efficient and scalable synthesis of the bioactive resveratrol trimer caraphenol A. That synthesis proceeded with an average yield of 89% per step (7.8% overall yield) and has provided access to more than 600 mg of the target molecule.
authors.forename: Nathan E
authors.initials: NE
authors.lastname: Wright
authors.forename: Scott A
authors.initials: SA
authors.lastname: Snyder
mesh_terms: D001688:Biological Products; D002384:Catalysis; D003500:Cyclization; D015394:Molecular Structure; D010636:Phenols / Q000138:chemical synthesis* / Q000737:chemistry; D000077185:Resveratrol; D013237:Stereoisomerism; D013267:Stilbenes / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D001688:Biological Products; D010636:Phenols; D013267:Stilbenes; D000077185:Resveratrol