title: Intramolecular Diels-Alder reactions using chiral ruthenium Lewis acids and application in the total synthesis of ent-ledol.
abstract: One-point binding chiral ruthenium Lewis acids incorporating the C(2)-symmetric electron-poor bidentate phosphinite ligand BIPHOP-F and a Cp or an indenyl 'roof' can efficiently catalyze asymmetric intramolecular Diels-Alder reactions of trienes to form bicyclic adducts with good to excellent asymmetric induction. This reaction forms the key step in a total synthesis of ent-ledol in 96% ee. The synthesis also helps to clarify the stereochemical assignment of ledol and inconsistencies in the measured optical rotation.
authors.affiliation: Department of Organic Chemistry, University of Geneva, 30 Quai Ernest Ansermet, CH-1211, Geneva, Switzerland.
authors.forename: Sirinporn
authors.initials: S
authors.lastname: Thamapipol
authors.forename: E Peter
authors.initials: EP
authors.lastname: Kündig
mesh_terms: D058116:Lewis Acids / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry*; D012717:Sesquiterpenes / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D058116:Lewis Acids; D009942:Organometallic Compounds; D012717:Sesquiterpenes; D012428:Ruthenium; C421806:ledol