title: Concise stereoselective synthesis of oxaspirocycles with 1-tosyl-1,2,3-triazoles: application to the total syntheses of (±)-Tuberostemospiroline and (±)-stemona-lactam R.
abstract: A 4-substituted-1-tosyl-1,2,3-triazole-based stereoselective synthesis of structurally diverse oxaspirocycles is reported. The synthesis involves Rh-catalyzed loss of nitrogen from 4-substituted-1-tosyl-1,2,3-triazoles, Grignard reaction, and a ring-closing metathesis reaction as key steps. By employing readily available and stable 4-substituted-1-tosyl-1,2,3-triazoles as surrogates of diazo compounds and nitrogen sources, two types of oxaspirocycles were obtained. The latter compounds, which contain adjacent nitrogen stereocenters, could serve as the core structures of many natural products. This chemistry has been successfully applied to the total syntheses of (±)-tuberostemospiroline and (±)-stemona-lactam R.
authors.affiliation: Laboratory of Chemical Genomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055 (China).
authors.forename: Junkai
authors.initials: J
authors.lastname: Fu
authors.forename: Hongjuan
authors.initials: H
authors.lastname: Shen
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Chang
authors.forename: Chuangchuang
authors.initials: C
authors.lastname: Li
authors.forename: Jianxian
authors.initials: J
authors.lastname: Gong
authors.forename: Zhen
authors.initials: Z
authors.lastname: Yang
mesh_terms: D001688:Biological Products / Q000138:chemical synthesis* / Q000737:chemistry; D003500:Cyclization; D007769:Lactams / Q000138:chemical synthesis* / Q000737:chemistry; D008958:Models, Molecular; D013141:Spiro Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D041901:Stemonaceae / Q000737:chemistry*; D013237:Stereoisomerism; D014230:Triazoles / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D001688:Biological Products; D007769:Lactams; D013141:Spiro Compounds; D014230:Triazoles; C588128:tuberostemospiroline
keywords: carbenes; oxaspirocycles; sigmatropic rearrangement; spiro compounds; total synthesis