| Abstract: | Two new stilbene tetramers, grandiphenols A ( 1 ) and B ( 2 ), along with ten known stilbene oligomers and bergenin were isolated from the stem of Dipterocarpus grandiflorus. The structures of 1 and 2 composed of four resveratrol (=5‐[(1E)‐2‐(4‐hydroxyphenyl)ethenyl]benzene‐1,3‐diol) units had eight asymmetric C‐atoms in the partial structures of a tetrahydrofuran and two dihydrobenzofuran moieties. Detailed spectroscopic analyses, especially HMBC and NOESY experiments, allowed to differentiate the configurations of 1 and 2 . |
