title: Synthesis of new chiral bis(isoxazoline) ligands containing spiro[5.5]undecane skeleton.
abstract: New chiral bis(isoxazoline) ligands bearing a spiro[5.5]undecane skeleton were designed and synthesized in five steps from diethyl malonate (3). These ligands showed a coordinating ability to Cu(II) as chiral ligands. A complex of (+)-(M*,S*,R*)-[5.5]-SPRIX 2b and Cu(OTf)(2) catalyzed the conjugate addition of diethyl-zinc to 2-cyclohexenone (8) to give (S)-3-ethyl-cyclohexanone (9) in 93% yield with 54% ee.
authors.affiliation: The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka, Japan.
authors.forename: Midori A
authors.initials: MA
authors.lastname: Arai
authors.forename: Minori
authors.initials: M
authors.lastname: Kuraishi
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Arai
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Sasai