Skip to main content
. Author manuscript; available in PMC: 2020 Jun 7.
Published in final edited form as: Org Chem Front. 2019 Apr 11;6(11):1762–1774. doi: 10.1039/C9QO00074G

Fig. 2.

Fig. 2.

Key connections determined from 2D NMR spectra for compound 1 (A), compounds 2 and 3 (B) and compound 4 (C). Bold bonds are used to show proton-proton connections determined through vicinal couplings, dashed bold bonds are used to show proton-proton connections determined through allylic and homoallylic couplings, and arrows are used to show HMBC correlations.