Complete assignment of the H-1 and C-13 NMR spectra of the tetraisoprenylated benzophenone 15-epiclusianone

An NMR study of 15-epiclusianone, 1-benzoyl-6-hydroxy-14,14-dimethyl-3,5,15 -tri(3-methyl-2-butenyl)bicyclo[3.3.1]non-1-ene-4,6-dione (1), a novel tetr aisoprenylated benzophenone isolated from pericarp of fruits of Rheedia gar dneriana, is described. In addition to conventional 1D NMR techniques, 2D s hift-correlated NMR experiments [H-1 x H-1-COSY, H-1 x C-13-HMQC-(1)J(C,H), H-1 x C-13-HMBC-(n)J(C,H) (n = 2 and 3) and H-1 x H-1-NOESY] were used for H-1 and C-13 chemical shift assignments of this natural product. The 1D C- 13 NMR spectrum of 1 in the solid state was also obtained. Copyright (C) 20 01 John Wiley & Sons, Ltd.