title: Total synthesis of colombiasin A and determination of its absolute configuration.
abstract: The total synthesis of the recently reported marine natural product colombiasin A (1) and determination of its absolute configuration are reported. Two Diels-Alder cycloadditions and a palladium-catalyzed rearrangement are employed as key reactions to construct the tetracyclic framework of the target molecule. The enantioselective synthesis of colombiasin A utilizes Mikami's [(S)-BINOL-TiCl2] catalyst to asymmetrically introduce the first chiral center during the initial Diels-Alder reaction and, in conjunction with X-ray crystallographic analysis of a bromine containing derivative, led to the assignment of the absolute configuration of the natural product.
authors.affiliation: Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA. kcn@scripps.edu
authors.forename: K C
authors.initials: KC
authors.lastname: Nicolaou
authors.forename: G
authors.initials: G
authors.lastname: Vassilikogiannakis
authors.forename: W
authors.initials: W
authors.lastname: Mägerlein
authors.forename: R
authors.initials: R
authors.lastname: Kranich
mesh_terms: D001952:Bridged-Ring Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D018360:Crystallography, X-Ray; D015394:Molecular Structure; D013057:Spectrum Analysis; D013237:Stereoisomerism
chemical_list: D001952:Bridged-Ring Compounds; C408889:colombiasin A