Calculated and experimental 1 H and 13 C NMR assignments for cannabicitran

Cannabicitran is an important cannabinoid natural product produced by Cannabis sativa and is often found at surprisingly high levels (up to ~10%) in "purified" commercial cannabidiol (CBD) extract preparations. Despite the prevalence of this molecule in CBD oil and other cannabinoid-related products, and the rapidly expanding interest in cannabinoids for treatment of a wide range of physiological conditions, only unassigned ¹ H NMR data and partial unambiguous ¹³ C assignments have been published. Herein, we report the complete ¹ H and ¹³ C NMR assignments of cannabicitran and comparatively evaluate the performance of several density functional theory (DFT) methods with varying levels of theory for the calculation of NMR chemical shifts.