Conformational analysis of 2-butanone and 3-methyl-2-butanone using lanthanide shift reagents

Lanthanide-induced 13C and 1H NMR chemical shift ratios of 2-butanone and 3-methyl-2-butanone have been determined using the shift reagent Yb(fod) 3. The induced shift data were analyzed to derive the conformational populations for these ketone-lanthanide chelate complexes. For 2-butanone, the cis c...

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Bibliographic Details
Published inJournal of magnetic resonance (1969) Vol. 40; no. 2; pp. 293 - 303
Main Authors Servis, Kenneth L, Shue, Feng Fang
Format Journal Article
LanguageEnglish
Published Elsevier Inc 01.01.1980
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Summary:Lanthanide-induced 13C and 1H NMR chemical shift ratios of 2-butanone and 3-methyl-2-butanone have been determined using the shift reagent Yb(fod) 3. The induced shift data were analyzed to derive the conformational populations for these ketone-lanthanide chelate complexes. For 2-butanone, the cis conformation (methyl eclipsing the carbonyl) was found to be more stable than the gauche conformation (hydrogen eclipsing the carbonyl). The equilibrium constant for cis conformation ⇋ gauche conformation is 0.7 at 37°C. For 3-methyl-2-butanone, however, no conclusion can be drawn from our data. Possible reasons for this difficulty are discussed.
ISSN:0022-2364
1557-8968
DOI:10.1016/0022-2364(80)90252-8