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Heating of [-)-quinic acid [[-)-ll at reflux temperature with 90% acetic acid/concd. H2S04 (6?/1) yields a mixture of six stereoisomeric quinic acids (four meso forms and two pairs of enantiomers), four y-quinides (four pairs of enantiomers), and three 6-quinides (two meso forms and one enantiomeric pair). The 'H-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 y-(lo) and 6-lactone (121, of epi-6-quinide (13), of two meso-quinic acids, and of another y-quinide is reported for the first time. The structures and configurations of neo-quinic acid, neo-y-, neo-6-, and epi-6-quinide are derived from their NMR spectra. All stereoisomeric quinic acids and their y-and &lactones are also formed under the roasting conditions of coffee.

The odor of most foods is produced by mixtures of many volatiie flavoring substances. Over the past century, numerous food flavors have been analyzed in sufficient detail to allow a survey of the classes of substances responsible, the formation of individual flavoring substances, and their fixation in the foods. In addition to special biosynthetic pathways, fhe breakdown of fats and the Maillard reaction have been found to be particularly important to the formation ojflavoring substances.