Cadinane-type sesquiterpenoids from Stahlianthus involucratus and their absolute configurations

Seven new cadinane-type sesquiterpenoids (1–7) were isolated from the rhizomes of Stahlianthus involucratus. The planar structures of 1–7 were elucidated on the basis of extensive spectroscopic and HRMS data. The absolute configuration of 1 was determined by the single-crystal X-ray diffraction, whereas those of C-9 in 3, C-9 in 4, C-6 in 6, and the 1,2-diol in 7 were deduced via the CD data of the in situ formed [Rh2(OCOCF3)4] complex, and Mo2(OAc)4-induced CD analysis, respectively.