title: External chiral ligand-induced enantioselective versions of the [2,3]-Wittig sigmatropic rearrangement.
abstract: The external chiral ligand-induced enantioselective [2,3]-Wittig rearrangements of crotyl benzyl ethers and crotyl propargylic ethers are described. The most notable is that treatment of (E)-crotyl propargylic ethers with a t-butyllithium/(S;S)-bis(oxazoline) complex provides a relatively high enantioselectivity (up to 89% ee), together with a high threo-diastereoselectivity. Furthermore, examples of the "asymmetric catalytic version" of the rearrangement of crotyl benzyl ethers are presented.
authors.affiliation: Department of Chemical Technology, Tokyo Institute of Technology, Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Tomooka
authors.forename: N
authors.initials: N
authors.lastname: Komine
authors.forename: T
authors.initials: T
authors.lastname: Nakai