title: Acyclic Stereoselection in the Ortho Ester Claisen Rearrangement.
abstract: The ortho ester Claisen rearrangement of trisubstituted allylic alcohols exhibits significant levels of diastereoselection. In E allylic alcohols, a 1,3-diaxial interaction develops in the chairlike transition state leading to the anti isomer, rendering the reaction syn selective by a factor of 3-5 to 1. In Z allylic alcohols, the 1,3-diaxial interaction develops in the transition state leading to the syn isomer, generating an anti:syn selectivity of 6-15 to 1. The relative stereochemistry of the syn isomer was confirmed independently by the synthesis of the mycotoxin botryodiplodin.
authors.affiliation: Department of Chemistry, Harvey Mudd College, Claremont, California 91711.
authors.forename: G. William
authors.initials: GW
authors.lastname: Daub
authors.forename: James P.
authors.initials: JP
authors.lastname: Edwards
authors.forename: Carol R.
authors.initials: CR
authors.lastname: Okada
authors.forename: Jana Westran
authors.initials: JW
authors.lastname: Allen
authors.forename: Claudia Tata
authors.initials: CT
authors.lastname: Maxey
authors.forename: Matthew S.
authors.initials: MS
authors.lastname: Wells
authors.forename: Alexandra S.
authors.initials: AS
authors.lastname: Goldstein
authors.forename: Michael J.
authors.initials: MJ
authors.lastname: Dibley
authors.forename: Clarence J.
authors.initials: CJ
authors.lastname: Wang
authors.forename: Daniel P.
authors.initials: DP
authors.lastname: Ostercamp
authors.forename: Steven
authors.initials: S
authors.lastname: Chung
authors.forename: Paula Shanklin
authors.initials: PS
authors.lastname: Cunningham
authors.forename: Martin A.
authors.initials: MA
authors.lastname: Berliner