title: Asymmetric intramolecular carbolithiation of achiral substrates: synthesis of enantioenriched (R)-(+)-cuparene and (R)-(+)-herbertene.
abstract: Concise syntheses of the sesquiterpenes (R)-(+)-cuparene and (R)-(+)-herbertene by asymmetric cyclization of achiral olefinic alkyllithium precursors in the presence of (-)-sparteine are reported. The quaternary stereogenic center in each product is set at the final step of the synthesis by enantioselective (er = 61:39) 5-exo ring closure.
authors.affiliation: Department of Natural Science, Mathematics, and Engineering, University of Pittsburgh at Greensburg , Greensburg, Pennsylvania 15601, United States.
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Luderer
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Mealy
authors.forename: William F
authors.initials: WF
authors.lastname: Bailey