Abstract
The 60 MHz <sup>1</sup>H NMR spectra of racemic vinclozolin, <i>1,</i> have been studied at 28° in CDCl<sub>3</sub> solution with the achiral reagent tris(6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionato)europium(III), <i>2,</i> and the chiral reagents tris[3-(trifluoromethylhydroxymethylene)-<i>d</i>-camphorato] europium(III), <i>3,</i> and tris[3-(heptafluoropropylhydroxymethylene)-<i>d</i>-camphorato]europium(III), <i>4.</i> Reagent <i>3</i> produced only small lanthanide-induced shifts and no observable enantiomeric shift differences, ΔΔδ, with <i>3:1</i> molar ratios as high as 1.40. In contrast, chiral reagent <i>4</i> produced substantial ΔΔδ for the proton, H<sub>β</sub>, at C-2 of the ethenyl group <i>syn</i> to the oxazolidinedione ring and smaller ΔΔδ for the <i>anti</i> proton, H<sub>β</sub>' at the above carbon and for the CH<sub>3</sub>. With a <i>4:1</i> molar ratio of 0.581, ΔΔδ of 7.0 Hz was seen for H<sub>β</sub>. A <i>4:1</i> ratio of about 0.41 should be optimum for optical purity determinations; as little as 5% of the minor enantiomer should be detectable.
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