title: Concise total synthesis of (±)-cephalotaxine via a transannulation strategy: development of a facile reductive oxy-Nazarov cyclization.
abstract: A concise total synthesis of (±)-cephalotaxine (1) has been achieved from dioxolanone derivative 15 via a transannulation strategy. The key transformation is a facile reductive oxy-Nazarov cyclization as illustrated above, involving presumably a tethered 1,2-oxidopentadienyl cation species 7a or 7b, which represents a new variant of the oxy-Nazarov cyclization and constitutes an effective, regio- and stereospecific 5-hydroxy cyclopentenone annulation protocol under mild hydride reduction conditions.
authors.affiliation: State Key Laboratory of Elemento-organic Chemistry, Nankai University, Tianjin 300071, P. R. China. wdli@nankai.edu.cn
authors.forename: Wei-Dong Z
authors.initials: WD
authors.lastname: Li
authors.forename: Wei-Guo
authors.initials: WG
authors.lastname: Duo
authors.forename: Cheng-Han
authors.initials: CH
authors.lastname: Zhuang
mesh_terms: D003500:Cyclization; D006248:Harringtonines / Q000138:chemical synthesis*; D000077863:Homoharringtonine; D015394:Molecular Structure; D010084:Oxidation-Reduction; D013237:Stereoisomerism
chemical_list: D006248:Harringtonines; D000077863:Homoharringtonine