Sesquiterpenoids and norsesquiterpenoids from three liverworts

Six new sesquiterpenoids and two new norsesquiterpenoids were isolated from the essential oils of three liverworts. The isolated compounds include (+)-eudesma-4,11-dien-8α-ol from the liverwort Diplophyllum albicans, (?)-4β,5β-diacetoxygymnomitr-3(15)-ene, (+)-5β-acetoxygymnomitr-3(15)-ene, (?)-15-acetoxygymnomitr-3-ene, (?)-3β,15β-epoxy-4β-acetoxygymnomitrane, and (?)-3α,15α-epoxy-4β-acetoxygymnomitrane from Marsupella emarginata, and (+)-1,2,3,6-tetrahydro-1,4-dimethylazulene and (?)-2,3,3a,4,5,6-hexahydro-1,4-dimethylazulen-4-ol from Barbilophozia floerkei. These compounds were isolated by a combination of different chromatographic techniques, and their structures were determined by extensive spectroscopic studies (MS, ¹H, ¹³C, and 2D NMR) and chemical transformations using enantioselective GC.