title: Asymmetric bromine-lithium exchange: application toward the synthesis of natural product.
abstract: Asymmetric bromine-lithium exchange has been successfully employed to synthesize bicoumarin chiral building blocks of (+)-isokotanin A and (-)-kotanin in good yields and with an excellent level of enantioselectivity. This is the first reported example of formal syntheses, using this direct methodology, leading to the single (M)-atropoisomer of (+)-isokotanin A and (-)-kotanin building blocks, without any resolution step.
authors.affiliation: Department of Organic Chemistry and Laboratory of Crystallography, University of Geneva, Quai Ernest Ansermet 30, Geneva 4, CH-1211 Switzerland.
authors.forename: Julien
authors.initials: J
authors.lastname: Graff
authors.forename: Thibaut
authors.initials: T
authors.lastname: Debande
authors.forename: Jézabel
authors.initials: J
authors.lastname: Praz
authors.forename: Laure
authors.initials: L
authors.lastname: Guénée
authors.forename: Alexandre
authors.initials: A
authors.lastname: Alexakis
mesh_terms: D001688:Biological Products / Q000138:chemical synthesis* / Q000737:chemistry; D001966:Bromine / Q000737:chemistry*; D002384:Catalysis; D003374:Coumarins / Q000138:chemical synthesis* / Q000737:chemistry; D008094:Lithium / Q000737:chemistry*; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D001688:Biological Products; D003374:Coumarins; C585762:isokotanin A; D008094:Lithium; D001966:Bromine