10.1002/mrc.1260310317
The research aims to provide a comprehensive analysis of the 13C NMR spectra of 91 labdane-type diterpenoid compounds, categorized into ten different series. The purpose of this study was to fill the gap in the literature regarding the compilation of 13C NMR data for labdane-type compounds, which could serve as models for the assignment of similar compounds in future research. Through the analysis of the 13C NMR spectra, the researchers observed consistent chemical shifts for the decalin system across various compounds and noted significant changes in chemical shifts when the side-chain contained oxygenated groups or double bonds in specific positions. The study utilized various labdane diterpenoids, including methyl mirceocommunate, methyl trans-communate, methyl cis-communate, and cis-abienol, which were subjected to reactions such as ozonolysis, oxymercuration-demercuration, hydroboration-oxidation, hydrogenation, epoxidation, and photooxidation to derive the compounds for analysis. The conclusions drawn from this research offer valuable insights into the structural elucidation of labdane-type compounds and contribute to the understanding of their NMR spectral characteristics.
