title: Explorations in organic chemistry leading to the total synthesis of (+/-)-gelsemine.
abstract: The total synthesis of (+/-)-gelsemine (1) is described. A defining phase of the effort involved recourse to a strategic oxetane ring (see compound 25). It was constructed anticipating an intramolecular displacement of the carbon (C17)-oxygen (O4) bond (see product 48). A key intermediate in the stereospecific elaboration of the oxetane linkage was enone 22, which was susceptible to two beta-face attacks leading to 24 and, thence, 25. Three sigmatropic rearrangements were employed in building the bridgehead (C20) and the spiroanilide (C7) quaternary centers en route to gelsemine.
authors.affiliation: Department of Chemistry, Columbia University, Havemeyer Hall, 3000 Broadway, New York, New York 10027, USA.
authors.forename: Fay W
authors.initials: FW
authors.lastname: Ng
authors.forename: Hong
authors.initials: H
authors.lastname: Lin
authors.forename: Pauline
authors.initials: P
authors.lastname: Chiu
authors.forename: Samuel J
authors.initials: SJ
authors.lastname: Danishefsky
mesh_terms: D000470:Alkaloids / Q000138:chemical synthesis*; D013237:Stereoisomerism
chemical_list: D000470:Alkaloids; C063230:gelsemine