title: Synthesis of enantiopure 3-quinuclidinone analogues with three stereogenic centers: (1S,2R,4S)- and (1S,2S, 4S)-2-(Hydroxymethyl)-1-azabicyclo[2.2.2]octan-5-one and stereocontrol of nucleophilic addition to the carbonyl group.
abstract: The pseudoenantiomeric title compounds have been prepared from quincorine (QCI) and quincoridine (QCD), respectively, in enantiopure form following an efficient six-step pathway. Nucleophilic attack at the carbonyl group proceeds preferentially from the supposedly more hindered endo pi-face, giving quinuclidinols with natural configuration at C5 (up to 97%). pi-Face selectivity is highest in the QCD series with bulky O-protecting groups, involving an unprecedented 1,7-stereoinduction.
authors.affiliation: Department of Organic Chemistry, University of Hannover, Schneiderberg 1B, D-30167 Hannover, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Frackenpohl
authors.forename: H M
authors.initials: HM
authors.lastname: Hoffmann
mesh_terms: D007202:Indicators and Reagents; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D011812:Quinuclidines / Q000138:chemical synthesis*; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
chemical_list: D007202:Indicators and Reagents; D011812:Quinuclidines