title: Organometallic enantiomeric scaffolding. Sequential semipinacol/1,5-"Michael-like" reactions as a strategic approach to bridgehead-quaternary center aza[3.3.1]bicyclics: application to the total synthesis of (-)-adaline.
abstract: A nontraditional approach to the enantiocontrolled construction of quaternary center-bearing heteroatom-bridged bicyclo[3.3.1]nonanes (homotropanes) is reported that is based on organometallic enantiomeric scaffolding. This strategy takes advantage of the unique reactivity profiles of TpMo(CO)(2)(5-oxo-eta(3)-pyranyl) and TpMo(CO)(2)(5-oxo-eta(3)-pyridinyl) scaffolds, and features a molybdenum-mediated semipinacol/1,5-"Michael-like" reaction sequence to establish the quaternary center and synthesize the bridged bicyclic structure. An asymmetric total synthesis of (-)-adaline highlights this methodology.
authors.affiliation: Sanford S. Atwood Chemistry Center, Emory University, 1515 Dickey Drive, Atlanta, Georgia 30322, USA.
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Coombs
authors.forename: Yongqiang
authors.initials: Y
authors.lastname: Zhang
authors.forename: Ethel C
authors.initials: EC
authors.lastname: Garnier-Amblard
authors.forename: Lanny S
authors.initials: LS
authors.lastname: Liebeskind
mesh_terms: D001372:Aza Compounds / Q000737:chemistry*; D001643:Bridged Bicyclo Compounds / Q000737:chemistry*; D001952:Bridged-Ring Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D010880:Piperidines / Q000138:chemical synthesis* / Q000737:chemistry; D011725:Pyridines / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D001372:Aza Compounds; D001643:Bridged Bicyclo Compounds; D001952:Bridged-Ring Compounds; D010880:Piperidines; D011725:Pyridines; C475960:adaline; C023666:pyridine