ISSN:
0170-2041
Keywords:
Quinic acid, stereoisomers of
;
Quinic acid γ-lactones
;
Quinic acid δ-lactones
;
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Heating of (-)-quinic acid [(-)-1] at reflux temperature with 90% acetic acid/concd. H2SO4 (67/1) yields a mixture of six stereoisomeric quinic acids (four meso forms and two pairs of enantiomers), four γ-quinides (four pairs of enantiomers), and three δ-quinides (two meso forms and one enantiomeric pair). The 1H- and 13C-NMR spectra for most of these compounds are given. The fully trimethylsilylated derivatives of all the compounds are characterized by high-resolution GC/MS. The existence of neo-quinic acid (6), its γ- (10) and δ-lactone (12), of epi-δ-quinide (13), of two meso-quinic acids, and of another γ-quinide is reported for the first time. The structures and configurations of neo-quinic acid, neo-γ-, neo-δ-, and epi-δ- quinide are derived from their NMR spectra. All stereoisomeric quinic acids and their γ-and δ-lactones are also formed under the roasting conditions of coffee.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jlac.1991199101177
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