Structures of merrilactones B and C, novel anislactone-type sesquiterpenes from Illicium merrillianum, and chemical conversion of anislactone B to merrilactone A

Two new anislactone-type sesquiterpenes, merrilactones B (1) and C (2) were isolated from the pericarps of Illicium merrillianum along with anislactones A (4) and B (5). Their structures were elucidated by spectroscopic methods and chemical transformation and the structure of merrilactone C was established by X-ray crystallographic analysis of its methyl derivative. Merrilactone A (3), a unique anislactone-type sesquiterpene showing neurite outgrowth promoting activity, was effectively synthesized from anislactone B.