Collect. Czech. Chem. Commun.
1978, 43, 2779-2799
https://doi.org/10.1135/cccc19782779
Use of structural changes for stereochemical assignments of natural α-exomethylene γ-lactones of the germacra-1(10),4-dienolide type on the basis of allylic and vicinal couplings of bridgehead protons. Hydrogenation of endocyclic double bonds
Zdeněk Samek and Juraj Harmatha