Dolabellane diterpenoids from the liverworts Barbilophozia floerkei, B. lycopodioides, and B. attenuata: spectroscopic and X-ray studies of structure, stereochemistry, and conformation. X-ray molecular structure of 3S,4S,7S,8S-diepoxy-10R,18-dihydroxydolabellane, 18-acetoxy-3S,4S;7S,8S-diepoxydolabellane, and 10R,18-diacetoxy-3S,4S-epoxydolabell-7E-ene - Huneck,S.; Baxter,G.A.; Cameron,A.F.; Connolly,J.D.; Harrison,L.J.; Phillips,W.R.; Rycroft,D.S.; Sim,G.A. (J Chem Soc Perkin Trans, 1986)