A quantitative structure-spectrum relationship (QSSR) model was developed to simulate 13C nuclear magnetic resonance (NMR) spectra of carbinol carbon atoms for 55 alcohols. The proposed model,using multiple linear reg...A quantitative structure-spectrum relationship (QSSR) model was developed to simulate 13C nuclear magnetic resonance (NMR) spectra of carbinol carbon atoms for 55 alcohols. The proposed model,using multiple linear regression,contained four descriptors solely extracted from the molecular structure of compounds. The statistical results of the final model show that R2= 0.982 4 and S=0.869 8 (where R is the correlation coefficient and S is the standard deviation). To test its predictive ability,the model was further used to predict the 13C NMR spectra of the carbinol carbon atoms of other nine compounds which were not included in the developed model. The average relative errors are 0.94% and 1.70%,respectively,for the training set and the predictive set. The model is statistically significant and shows good stability for data variation as tested by the leave-one-out (LOO) cross-validation. The comparison with other approaches also reveals good performance of this method.展开更多
Five nopyl ethers and two nopyl esters have been synthesized, and their 13 C NMR spectra have been recorded. The C 6, C 7 chemical shifts in their 13 C NMR spectra have been discussed in terms of configuration structu...Five nopyl ethers and two nopyl esters have been synthesized, and their 13 C NMR spectra have been recorded. The C 6, C 7 chemical shifts in their 13 C NMR spectra have been discussed in terms of configuration structure. It is suggested that the C 1, C 2, C 3, C 4 and C 5 atoms are in the same plan and the 6,6 dimethylbicyclohept 2 ene part is in the Y shape. The ethers and esters obtained appeared to be derivatives of apopinene 6,6 dimethylbicyclohept 2 ene with substituents at the C 2 position . The effect of substituents occured mainly on the chemical shifts of C 1, C 2 and C 3. There seemes a weaker steric interaction of the substituents with other carbon atoms.展开更多
基金Projects(20775010, 21075011) supported by the National Natural Science Foundation of ChinaProject(2008AA05Z405) supported by the National High-tech Research and Development Program of China+2 种基金Project(09JJ3016) supported by the Natural Science Foundation of Hunan Province, ChinaProject(09C066) supported by the Scientific Research Fund of Hunan Provincial Education Department, ChinaProject(2010CL01) supported by the Foundation of Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation, China
文摘A quantitative structure-spectrum relationship (QSSR) model was developed to simulate 13C nuclear magnetic resonance (NMR) spectra of carbinol carbon atoms for 55 alcohols. The proposed model,using multiple linear regression,contained four descriptors solely extracted from the molecular structure of compounds. The statistical results of the final model show that R2= 0.982 4 and S=0.869 8 (where R is the correlation coefficient and S is the standard deviation). To test its predictive ability,the model was further used to predict the 13C NMR spectra of the carbinol carbon atoms of other nine compounds which were not included in the developed model. The average relative errors are 0.94% and 1.70%,respectively,for the training set and the predictive set. The model is statistically significant and shows good stability for data variation as tested by the leave-one-out (LOO) cross-validation. The comparison with other approaches also reveals good performance of this method.
文摘Five nopyl ethers and two nopyl esters have been synthesized, and their 13 C NMR spectra have been recorded. The C 6, C 7 chemical shifts in their 13 C NMR spectra have been discussed in terms of configuration structure. It is suggested that the C 1, C 2, C 3, C 4 and C 5 atoms are in the same plan and the 6,6 dimethylbicyclohept 2 ene part is in the Y shape. The ethers and esters obtained appeared to be derivatives of apopinene 6,6 dimethylbicyclohept 2 ene with substituents at the C 2 position . The effect of substituents occured mainly on the chemical shifts of C 1, C 2 and C 3. There seemes a weaker steric interaction of the substituents with other carbon atoms.
