The synthesis of diversifolide and its structural revision are reported. We synthesized the assigned structure of diversifolide via two methods, but the NMR spectra of the synthetic material did not match those of the natural material. Through careful investigation, we found that the spectra were identical with those of 11-epi-sundiversifolide. (C) 2008 Elsevier Ltd. All rights reserved.
The total synthesis and determination of the absolute configuration of (+)- and (-)-sundiversifolide have been achieved via intramolecular acylation and Wittig-lactonization as the key steps. The xanthanolide sesquiterpene lactones, 8-epi-xanthatin (1), dihydroxanthatin (2), and xanthatin (3) were also prepared, starting from a common intermediate derived from the synthesis of sundiversifolide. (C) 2010 Elsevier Ltd. All rights reserved.