ISSN:
1434-4475
Keywords:
Triacetylcellulose
;
Recycling technique
;
Enantiomeric purity
;
Metallocene chirality
;
Axial chirality
;
Conformation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Chiral title compounds have been resolved by medium pressure liquid chromatography (MPLC) on triacetylcellulose in ethanol. Whereas a quantitative separation was achieved for16 and20, a recycling technique had to be applied to1,4,6,10 and15 leading to a 100% e.e. for1,6 and15 and to ca. 60% e.e. for4 and10. An unambiguous assignment of the chirality (+)-(R) a -(S) m for tricarbonylchromium-6,6′-dimethyl-diphenicacid dimethylester (4) was deduced both from the photochemical decomplexation to (-)-5 with the known chirality (R) a (whose e.e. was determined by MPLC on triacetylcellulose) and by comparison of the1H-n.m.r. spectra of4 and5 thereby proving the structure 4 for the former. Other chiralities both for mono and bis(tricarbonylchromium)biphenyl complexes were established by chemical correlations and comparison of the CD spectra with those of key compounds.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00816342