The following experiments have provided some information concerning the configuration of alantolactone. Alantolactone is probably a trans-decaline, since Ukita and Naka~ awa'~ have recently converted it to sesquibenihiol derivatives and the latter had previously been correlated with selinene by Katsura. ll Both the keto ester IX5e and the keto acid XI11 derived from IX by saponification give the original tetrahydroalantolactone on reduction ...
