title: An asymmetric ortholithiation approach to inherently chiral calix[4]arenes.
abstract: A general asymmetric synthesis of inherently chiral calix[4]arenes is described: using a chiral oxazoline derived from L-valine, an ortholithiation strategy is employed to give inherently chiral calix[4]arenes with high (93%) enantiomeric excesses. A crystal structure of a phosphine oxide intermediate has been obtained, unambiguously assigning the major diastereomer in the reaction; a mechanism explaining this result is proposed.
authors.affiliation: Department of Chemistry and Polymer Science, University of Stellenbosch, Matieland 7602, South Africa.
authors.forename: Simon A
authors.initials: SA
authors.lastname: Herbert
authors.forename: Gareth E
authors.initials: GE
authors.lastname: Arnott