title: Stereodivergent synthesis of fused bicyclopyrazolidines: access to pyrazolines and pyrrolidines.
abstract: The reaction of hydrazinoethyl 1,1-cyclopropanediesters with aldehydes in the presence of catalytic Yb(OTf)(3) allows access to structurally complex fused bicyclo pyrazolidines. Either 2,5-cis or 2,5-trans adducts can be obtained in good to excellent yields in most cases by simply controlling the order of addition of the catalyst and aldehyde.
authors.affiliation: Department of Chemistry, The University of Western Ontario, London, Ontario, Canada N6A 5B7.
authors.forename: Terry P
authors.initials: TP
authors.lastname: Lebold
authors.forename: Michael A
authors.initials: MA
authors.lastname: Kerr
mesh_terms: D008968:Molecular Conformation; D011720:Pyrazoles / Q000138:chemical synthesis* / Q000737:chemistry*; D011759:Pyrrolidines / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D011720:Pyrazoles; D011759:Pyrrolidines