title: Synthesis of enantiomerically pure (2S,3S)-5,5,5-trifluoroisoleucine and (2R,3S)-5,5,5-trifluoro-allo-isoleucine.
abstract: A practical route for the stereoselective synthesis of (2S,3S)-5,5,5-trifluoroisoleucine (L-5-F3Ile) and (2R,3S)-5,5,5-trifluoro-allo-isoleucine (D-5-F3-allo-Ile) was developed. The hydrophobicity of L-5-F3Ile was examined and it was incorporated into a model peptide via solid phase peptide synthesis to determine its α-helix propensity. The α-helix propensity of 5-F3Ile is significantly lower than Ile, but surprisingly high when compared with 4'-F3Ile.
authors.affiliation: Department of Chemistry and Biochemistry, Freie Universität Berlin, Takustr. 3, 14195 Berlin, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Erdbrink
authors.affiliation: Department of Chemistry and Biochemistry, Freie Universität Berlin, Takustr. 3, 14195 Berlin, Germany.
authors.forename: Elisabeth K
authors.initials: EK
authors.lastname: Nyakatura
authors.affiliation: Department of Chemistry and Biochemistry, Freie Universität Berlin, Takustr. 3, 14195 Berlin, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Huhmann
authors.affiliation: Department of Chemistry and Biochemistry, Freie Universität Berlin, Takustr. 3, 14195 Berlin, Germany.
authors.forename: Ulla I M
authors.initials: UIM
authors.lastname: Gerling
authors.affiliation: Department of Chemistry and Biochemistry, Freie Universität Berlin, Takustr. 3, 14195 Berlin, Germany.
authors.forename: Dieter
authors.initials: D
authors.lastname: Lentz
authors.affiliation: Department of Chemistry and Biochemistry, Freie Universität Berlin, Takustr. 3, 14195 Berlin, Germany.
authors.forename: Beate
authors.initials: B
authors.lastname: Koksch
authors.affiliation: Department of Chemistry and Biochemistry, Freie Universität Berlin, Takustr. 3, 14195 Berlin, Germany.
authors.forename: Constantin
authors.initials: C
authors.lastname: Czekelius
keywords: CD-spectroscopy; amino acids; fluorine; helix propensity; organo-fluorine; trifluoroisoleucine