Calculated energy differences between cis-and transfused bicyclic ketones are provided for bicyclo[3.3.0]octanones, bicyclo[4.3.0]nonanones, bicyclo[5.3.0]decanones, bicyclo[6.3.0]undecanones and the corresponding hydrocarbons with and without angular methyl groups. The calculations were performed for HF/6-31G* and MP2/6-31G* optimized geometries. The latter were used for subsequent single-point energy MP2/6-311G* calculations. Whenever possible, the calculated energy differences were compared with experimental data and found to correspond well. The results of the calculations provide a complete picture of expected energetic differences in bicyclic ketone series and will be useful in both instruction and synthetic planning.

To characterize the flavor preferences of weanling pigs, a T-maze test was designed and validated. After having sampled feed from one side, containing flavor, and the other side, containing no flavor, pigs were allowed to select feed from either side of the T-maze five times. The frequency of selecting the flavored feed and the percentage of total feed eaten in 20 s/run were used to establish degree of preference for flavors. A total of 129 flavors or flavor combinations was tested in 248 trials, with some flavors tested at several concentrations. At least four flavors were tested in each of eight major flavor groups; the frequency distribution of preference did not differ among groups. Five specific flavors, highly preferred by the pigs in the T-maze tests, were selected for sustained preference tests for two 5-d periods. In the tests, a preference was shown for three of the five flavors. Two flavors were then tested for effects on performance using three groups of 10 pigs for 5 wk after weaning. The feed intakes and body weight gains were increased during the first week in both groups fed flavored feed compared with those of the control group. In a growth trial with 1,219 pigs, one of the two flavors increased feed intake and improved weight gain during the first week after weaning. Thus, although pigs did not appear to prefer flavors in any one of the groups tested, they did prefer specific flavors, which, when added to feed, improved feed intake and weight gain during the critical first week after weaning.

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The infrared spectra of 72 highly purified acyclic, monocyclic and bicyclic terpenes and their hydrogenated derivatives are presented. These spectra provide a broad basis for the correlation of structure and spectra.