Synthesis, resolution, and absolute configuration of difunctionalized Tröger's base derivatives.
Two racemic derivatives of Tröger's base, the 2,8-diboronic acid ester 6 and the 3,9-dibromo-substituted derivative 5, were synthesized and successfully resolved by HPLC on a chiral stationary Whelk-01 phase on a semipreparative scale, thereby giving rise to both enantiomers in a pure form. These functionalized C(2)-symmetric building blocks are valuable precursors for a variety of further applications. Their absolute configurations were determined by comparison of their quantum chemically calculated CD and UV/Vis spectra with the experimental ones and were independently confirmed by X-ray diffraction analysis.
Kiehne
Ulf
U
Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany.
Bruhn
Torsten
T
Schnakenburg
Gregor
G
Fröhlich
Roland
R
Bringmann
Gerhard
G
Lützen
Arne
A