NMR Spectrum

Prediction： NMR spectra: The three nonequivalent protons of the 17-pyrazine moiety in Compound 14 appeared as three singlets at delta 8.35, 8.48 and 8.70, while for the three protons of the 17-pyrimidine moiety in Compound 15, two equivalent protons appear as a singlet at delta 8.73 and one proton appeared at delta 9.07. Furthermore, the 17-diazine groups of Compounds 14 and 15 exhibit different influences on the chemical shifts of their respective 16-olefinic protons with respect to the 16-proton of the precursor delta1 -17-iodide 13: the 16-eta in Compound 14 appeared as a singlet at delta 6.77, being significantly deshielded compared to the 16-H in Compound 13 (delta 6.14); the 16-H in Compound 15 appeared at delta 6.11, similar to Compound 13.

    ¹H NMR

¹³C NMR