The 13C-NMR features of natural taxane diterpenoid compounds

The paper reviewed the C-13-NMR features of natural taxane diterpenoids according to their carbon-skeleton types. In the C-13-NMR it is easy to distinguish the 6/8/6 and 5/7/6 membered rings by observation of the C-13-NMR data of C-1 and C-15. The remarkable differences of the resonance of C-13 and C-12 were found. In addition, based on various chemical environments many obscured chemical shifts of carbons can be distinguished, such as the oxygenated tertiary carbons of C-2, C-5, C-7, C-9 and C-13, and sometimes between C-9 and C-10, as well as between aliphatic quaternary carbons of C-8 and C-15, and secondary carbons of C-6 and C-14. AU the above-mentioned characteristics are helpful for structural elucidation and assignments of the carbon signals of taxoids.