as test examples for the best classifiers mentioned above. Their structures are shown in Figure . Table summarizes the 1 H NMR spectral features while It is interesting to notice that all models misclassified the ether at 4.50 ppm in the Oxolan-3-one structure, the SMOTE-ET model predicted an alcohol group while the four other models predicted a benzylic group. This can be explained by looking at the confusion matrices of the models, where one can see that, for the SMTOE-ET model, five ethers from the test partition of the database were predicted as alcohols. On the other hand, the confusion matrices of the other models showed that at least one ether of the test partition was predicted as a benzylic group.