Novel diterpenoids from Croton cascarilloides

摘要

Although only a few of the examples of crotofolanes have been reported.1,2) from Crown cascarilloides we reported the isolation of a great number of crotofolanes. nor-crotofolanes. 3) and novel diterpenoids with new skeletons. From continuing our study, we isolated a new rearranged nor-crotofolane (4) and further three new crotofolanes (15, 17 and 28) from an EtOAc-soluble fraction of the leaves. Structures of these compounds were elucidated by spectroscopic analyses. In addition, the absolute structures of some of these compounds were determined by X-ray crystallographic analysis.