DFT approach towards accurate prediction of ¹H/¹³C NMR chemical shifts for dipterocarpol oxime.

ABSTRACT: A computational NMR approach for accurate predicting the ¹H/¹³C chemical shifts of triterpenoid oximes featuring the screening of 144 DFT methods was demonstrated. Efficiently synthesized dipterocarpol oxime was employed as a model compound. The six highest accurate methods from the screening generated root-mean-square-error (RMSE) values in the range of 0.84 ppm (0.55%) to 1.14 ppm (0.75%) for calculated ¹³C shifts. For ¹H results, simple, economical 6-31G basis set unexpectedly outperformed other more expensive basic sets; and the couple of it with selected functionals provided high accuracy shifts (0.0617 ppm (1.49%) ≤ RMSE ≤ 0.0870 ppm (2.04%)). These computational results strongly supported the proton and carbon assignments of the oxime incl

SUBMITTER: Le PQ 

PROVIDER: S-EPMC10613955 | biostudies-literature | 2023 Oct

REPOSITORIES: biostudies-literature